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Добірка наукової літератури з теми "Single muscle fibres"

Автор: Grafiati

Опубліковано: 10 січня 2023

Оновлено: 28 січня 2023

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Статті в журналах з теми "Single muscle fibres"

Kernell, Daniel. "Muscle Regionalization." Canadian Journal of Applied Physiology 23, no. 1 (February 1, 1998): 1–22. http://dx.doi.org/10.1139/h98-001.

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In this review, the term muscle fibre regionalization signifies the presence of regional intramuscular differences in fibre type composition. As is well known, highly regionalized muscles commonly have greater concentrations of slow fibres deep than superficially. However, the degree of regionalization varies markedly between muscles and is not confined to deep vs. superficial locations. Fibres of the same myosin type may show regionalized differences in their metabolic enzyme activity, even within single motor units (Larsson, 1992). Regionalization of fibre type composition occurs also within single neuromuscular partitions. The intraspinal position of motoneurones is often coarsely related to the intramuscular sites of their muscle units. Muscles with a marked fibre type regionalization tend to show a corresponding regionalization of activity; in several muscles, however, the activity regionalization may vary depending on the motor task. During early development, fibre type regionalization emerges even under aneural conditions. The mechanisms are still unknown; relevant aspects of early development are briefly reviewed. Key words: skeletal muscle, fiber type, topography, activity, development

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Velotto, Salvatore, Ettore Varricchio, Maria Rosa Di Prisco, Tommaso Stasi, and Antonio Crasto. "Effect of Age and Sex on Histomorphometrical Characteristics of Two Muscles of Laticauda Lambs." Acta Veterinaria Brno 79, no. 1 (2010): 3–12. http://dx.doi.org/10.2754/avb201079010003.

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The aim of the present experiment was to determine the effect of sex and age on histochemical and morphometric characteristics of muscle fibres (myocytes) in lambs born by single, twin, triplet and quadruplet birth. Thirty lambs were slaughtered at 60 days of age; thirty were weaned at 60 days and fed until 120 days with flakes (60%) and food supplements, and then slaughtered. Muscle tissues were obtained from two muscles, namely m. semitendinosus and m. longissimus dorsi of all lambs. For each fibre type, area perimeter and diameter (maximum and minimum) were measured and slow-twitch oxidative fibres, fast-twitch glycolytic fibres, fast-twitch oxidative-glycolytic fibres were histochemically differentiated. The muscles were stained for myosin ATPase, and succinic dehydrogenase. At 60 days, females had fibres larger than males, whereas the opposite was observed at 120 days. Besides, at 60 days, the lambs born by single birth had fibres larger than those born by multiple birth, whereas the opposite was observed at 120 days. Single lambs were heavier than twin lambs and multiple lambs. Fast-twitch glycolytic fibres had the largest size, followed by slow-twitch oxidative and fast-twitch oxidative glycolytic fibres. The dimensions of fibre types in m. longissimus dorsi were larger than in m. semitendinosus (P < 0.001).These muscle fibre characteristics are thought to be important factors influencing meat quality, which is often related to metabolic and contractile properties as determined by the muscle fibre type distribution.

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Neil, D. M., W. S. Fowler, and G. Tobasnick. "MYOFIBRILLAR PROTEIN COMPOSITION CORRELATES WITH HISTOCHEMISTRY IN FIBRES OF THE ABDOMINAL FLEXOR MUSCLES OF THE NORWAY LOBSTER NEPHROPS NORVEGICUS." Journal of Experimental Biology 183, no. 1 (October 1, 1993): 185–202. http://dx.doi.org/10.1242/jeb.183.1.185.

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The myofibrillar proteins in fibres from the abdominal flexor muscles of the Norway lobster, Nephrops norvegicus, have been identified using SDS-PAGE gel electrophoresis. Several contractile and regulatory proteins are expressed as multiple isoforms in single fibres and, according to these, one fast fibre phenotype (F) can be identified in the deep flexor muscles and two slow fibre phenotypes (S1 and S2) can be distinguished in the superficial flexor muscles. The two slow fibre phenotypes are distributed non-uniformly across the superficial flexor muscle, and in the lateral bundle there is a heterogeneous mixture of both S1 and S2 fibres. Using histochemical procedures applied to intact or freeze-dried fibres in conjunction with measurements of fibre sarcomere length and gel electrophoresis, an exact correspondence can be demonstrated between the morphological properties, enzymatic content and myofibrillar protein composition of individual fibres from the deep and superficial flexor muscles. In the superficial flexor muscle, fibres of the S1 phenotype have a mean sarcomere length of <8 micrometre, a low oxidative capacity and an acid-labile isoform of myosin ATPase, while fibres of the S2 phenotypes have a longer sarcomere length (mean >9 micrometre), a higher oxidative capacity and an acid-stable isoform of myosin ATPase. These results are discussed in terms of the relationships between the different muscle fibre properties and the usefulness of procedures applied to single fibres for determining them.

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Velotto, Salvatore, Claudia Vitale, Tommaso Stasi, and Antonio Crasto. "New Insights into Muscle Fibre Types in Casertana Pig." Acta Veterinaria Brno 79, no. 2 (2010): 169–76. http://dx.doi.org/10.2754/avb201079020169.

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Little is known about the Casertana pig. The aim of this study was to evaluate the effect of sex on histochemical and morphometrical characteristics of muscle fibres (myocytes) in this pure breed and to verify the presence of giant fibres as well as vascularity of the muscle. Finally, maximum shortening velocity and isometric tension were measured in single muscle fibres. Sixteen Casertana pigs (8 males, 8 females) from a farm in Campania (Italy) were slaughtered at one year of age. Muscle tissues were obtained from psoas minor, rhomboideus and longissimus dorsi. Myofibres were stained for myosin adenosine triphosphatase, succinic dehydrogenase, and α-amylase-periodic acid schiff. For all fibre types, the area and perimeter were measured. Slowtwitch oxidative fibres, fast-twitch glycolytic fibres and fast-twitch oxidative-glycolytic fibres were histochemically differentiated; an image-analyzing system was used. The results showed significant differences between the sexes in the size of all three fibre types. The psoas minor muscle had a high percentage of slow-twitch oxidative fibres and contained more capillaries per fibre and per mm2 than rhomboideus and longissimus dorsi, in which fast-twitch glycolytic fibres dominated. The cross-sectional area of all fibre types was larger in longissimus dorsi than in rhomboideus and psoas minor muscles; the giant fibres were present in the longissimus dorsi muscle only. Besides, isometric tension values were higher in fast-twitch glycolytic fibres than in the other ones. Variations in fibre type composition may contribute to meat quality.

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Westwood, F. Russell, Alison Bigley, Kevin Randall, Alan M. Marsden, and Robert C. Scott. "Statin-Induced Muscle Necrosis in the Rat: Distribution, Development, and Fibre Selectivity." Toxicologic Pathology 33, no. 2 (February 2005): 246–57. http://dx.doi.org/10.1080/01926230590908213.

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Simvastatin and cerivastatin have been used to investigate the development of statin-induced muscle necrosis in the rat. This was similar for both statins and was treatment-duration dependent, only occurring after 10 days had elapsed even if the dose was increased, and still occurring after this time when dosing was terminated earlier as a result of morbidity. It was then widespread and affected all areas of the muscular system. However, even when myotoxicity was severe, particular individual muscles and some types of fibres within affected muscles were spared consistently. Fibre typing of spared muscles and of acutely necrotic fibres within affected muscles indicated a differential fibre sensitivity to statin-induced muscle necrosis. The fibres showed a necrotic response to statin administration that matched their oxidative/glycolytic metabolic nature: Least sensitive →I ↔ IIA ↔ IID ↔ IIB ← most sensitive. Type I and IIB fibres represent metabolic extremes of a continuum of metabolic properties through the fibre types with type I fibres most oxidative in metabolism and type IIB fibres most glycolytic. In addition, in some (nonnecrotic) glycolytic fibres from muscles showing early multifocal single fibre necrosis the only subcellular alterations present in isolation of any other changes were mitochondrial. These changes were characterised by an increased incidence of vacuolation and the formation of myelinoid vesicular bodies that accumulated in the subsarcolemmal areas. These findings suggest an important early involvement of mitochondria in selective glycolytic muscle fibre necrosis following inhibition of the enzyme HMG-CoA reductase.

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Gunzel, D., S. Galler, and W. Rathmayer. "FIBRE HETEROGENEITY IN THE CLOSER AND OPENER MUSCLES OF CRAYFISH WALKING LEGS." Journal of Experimental Biology 175, no. 1 (February 1, 1993): 267–82. http://dx.doi.org/10.1242/jeb.175.1.267.

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1. The closer and opener muscles in the third walking legs of the three crayfish Pacifastacus leniusculus, Procambarus clarkii and Astacus leptodactylus are composed of fibres which differ in histochemistry, electrophysiology and morphology. Three major groups of fibres (A, B and C) were distinguished. 2. Group A fibres react weakly to histochemical stains for myofibrillar ATPase (mATPase) activity characteristic of fibres with slow shortening speeds. In the opener muscle, they are innervated by the opener excitor (OE) and the specific opener inhibitor (OI). In the closer muscle, group A fibres are innervated by the common inhibitory neurone (CI) in addition to single (slow closer excitor, SCE) or double excitatory (SCE and fast closer excitor, FCE) innervation. Group A fibres have the largest excitatory junction potentials (EJPs), the longest membrane time constants (tau) and the longest sarcomeres. They are located at the very distal and proximal ends of both muscles. 3. Group B fibres show higher mATPase activity than group A fibres. In the opener muscle, they are innervated by OE and OI; in the closer muscle, they receive double excitatory (SCE and FCE) and CI innervation. Single SCE and OE EJPs are small; those caused by FCE are larger. tau is shorter than in the other two fibre groups. Sarcomere lengths lie between those of group A and C fibres. Group B fibres are found along the entire lengths of both muscles. 4. Group C fibres exhibit the highest mATPase activity (characteristic of fibres with fast shortening velocity) which, in contrast to the ATPase of group B fibres, is not resistant to alkaline preincubation at pH 10.05. In the closer, these fibres lack innervation by CI, otherwise the innervation pattern is identical to that of group B fibres. EJP size is similar to that of group B fibres; tau ranges between values for group A and B fibres. Sarcomere lengths are the shortest of all the fibre types. Group C fibres constitute the majority of the fibres in the two muscles and mainly occupy the central regions.

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Michael, Mena, Larisa Kovbasyuk, Paul Ritter, Michael B. Reid, Oliver Friedrich, and Michael Haug. "Redox Balance Differentially Affects Biomechanics in Permeabilized Single Muscle Fibres—Active and Passive Force Assessments with the Myorobot." Cells 11, no. 23 (November 22, 2022): 3715. http://dx.doi.org/10.3390/cells11233715.

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An oxidizing redox state imposes unique effects on the contractile properties of muscle. Permeabilized fibres show reduced active force generation in the presence of H2O2. However, our knowledge about the muscle fibre’s elasticity or flexibility is limited due to shortcomings in assessing the passive stress–strain properties, mostly due to technically limited experimental setups. The MyoRobot is an automated biomechatronics platform that is well-capable of not only investigating calcium responsiveness of active contraction but also features precise stretch actuation to examine the passive stress–strain behaviour. Both were carried out in a consecutive recording sequence on the same fibre for 10 single fibres in total. We denote a significantly diminished maximum calcium-saturated force for fibres exposed to ≥500 µM H2O2, with no marked alteration of the pCa50 value. In contrast to active contraction (e.g., maximum isometric force activation), passive restoration stress (force per area) significantly increases for fibres exposed to an oxidizing environment, as they showed a non-linear stress–strain relationship. Our data support the idea that a highly oxidizing environment promotes non-linear fibre stiffening and confirms that our MyoRobot platform is a suitable tool for investigating redox-related changes in muscle biomechanics.

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Sokoloff, A. J., and G. E. Goslow. "Neuromuscular organization of avian flight muscle: architecture of single muscle fibres in muscle units of the pectoralis (pars thoracicus) of pigeon (Columba livia)." Philosophical Transactions of the Royal Society of London. Series B: Biological Sciences 354, no. 1385 (May 29, 1999): 917–25. http://dx.doi.org/10.1098/rstb.1999.0443.

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The M. pectoralis (pars thoracicus) of pigeons ( Columba livia ) is comprised of short muscle fibres that do not extend from muscle origin to insertion but overlap ‘in-series’. Individual pectoralis motor units are limited in territory to a portion of muscle length and are comprised of either fast twitch, oxidative and glycolytic fibres (FOG) or fast twitch and glycolytic fibres (FG). FOG fibres make up 88 to 90% of the total muscle population and have a mean diameter one-half of that of the relatively large FG fibres. Here we report on the organization of individual fibres identified in six muscle units depleted of glycogen, three comprised of FOG fibres and three comprised of FG fibres. For each motor unit, fibre counts revealed unequal numbers of depleted fibres in different unit cross-sections. We traced individual fibres in one unit comprised of FOG fibres and a second comprised of FG fibres. Six fibres from a FOG unit (total length 15.45 mm) ranged from 10.11 to 11.82 mm in length and averaged (±s.d.) 10.74±0.79 mm. All originated bluntly (en mass) from a fascicle near the proximal end of the muscle unit and all terminated intramuscularly. Five of these ended in a taper and one ended bluntly. Fibres coursed on average for 70% of the muscle unit length. Six fibres from a FG unit (total length 34.76 mm) ranged from 8.97 to 18.38 mm in length and averaged 15.32 ±3.75 mm. All originated bluntly and terminated intramuscularly; one of these ended in a taper and five ended bluntly. Fibres coursed on average for 44% of the muscle unit length. Because fibres of individual muscle units do not extend the whole muscle unit territory, the effective cross-sectional area changes along the motor unit length. These non-uniformities in the distribution of fibres within a muscle unit emphasize that the functional interactions within and between motor units are complex.

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Jee, Hyunseok, and Jae-Young Lim. "Discrepancies between Skinned Single Muscle Fibres and Whole Thigh Muscle Function Characteristics in Young and Elderly Human Subjects." BioMed Research International 2016 (2016): 1–8. http://dx.doi.org/10.1155/2016/6206959.

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We aimed to analyse the mechanical properties of skinned single muscle fibres derived from the vastus lateralis (VL) muscle in relation to those of the whole intact thigh muscle and to compare any difference between young and older adults. Sixteen young men (29.25±4.65years), 11 older men (71.45±2.94years), 11 young women (29.64±4.88years), and 7 older women (67.29±1.70years) were recruited. In vivo analyses were performed for mechanical properties such as isokinetic performance, isometric torque, and power. Specific force and maximum shortening velocity (Vo) were measured with single muscle fibres. Sex difference showed greater impact on the functional properties of both the whole muscle (p<0.01) and single muscle fibres than aging (p<0.05). Sex difference, rather than aging, yielded more remarkable differences in gross mechanical properties in the single muscle fibre study in which significant differences between young men and young women were found only in the cross-sectional area and Vo (p<0.05). Age and sex differences reflect the mechanical properties of both single muscle fibres and whole thigh muscle, with the whole muscle yielding more prominent functional properties.

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Staron, R. S., and D. Pette. "The multiplicity of combinations of myosin light chains and heavy chains in histochemically typed single fibres. Rabbit tibialis anterior muscle." Biochemical Journal 243, no. 3 (May 1, 1987): 695–99. http://dx.doi.org/10.1042/bj2430695.

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1. Combined histochemical and biochemical single-fibre analyses [Staron & Pette (1987) Biochem. J. 243, 687-693], were used to investigate the rabbit tibialis-anterior fibre population. 2. This muscle is composed of four histochemically defined fibre types (I, IIC, IIA and IIB). 3. Type I fibres contain slow myosin light chains LC1s and LC2 and the slow myosin heavy chain HCI, and types IIA and IIB contain the fast myosin light chains LC1f, LC2f and LC3f and the fast heavy chains HCIIa and HCIIb respectively. 4. A small fraction of fibres (IIAB), histochemically intermediate between types IIA and IIB, contain the fast light myosin chains but display a coexistence of HCIIa and HCIIb. 5. Similarly to the soleus muscle, C fibres in the tibialis anterior muscle contain both fast and slow myosin light chains and heavy chains. The IIC fibres show a predominance of the fast forms and the IC fibres (histochemically intermediate between types I and IIC) a predominance of the slow forms. 6. A total of 60 theoretical isomyosins can be derived from these findings on the distribution of fast and slow myosin light and heavy chains in the fibres of rabbit tibialis anterior muscle.

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Більше джерел

Дисертації з теми "Single muscle fibres"

Vawda, Farouk. "Effects of hydrostatic pressure on single intact muscle fibres." Thesis, University of Bristol, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.294625.

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Kalakoutis, Michaeljohn. "Specific force in human single muscle fibres with specific reference to ageing." Thesis, King's College London (University of London), 2017. https://kclpure.kcl.ac.uk/portal/en/theses/specific-force-in-human-single-muscle-fibres-with-specific-reference-to-ageing(99224606-619b-46f8-87d4-a175a2ade014).html.

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The loss of muscle strength in the elderly is greater than the loss of muscle mass, termed specific force (SF) loss, and indicates that a decrease in muscle quality contributes to age-related muscular weakness. The present PhD thesis has studied age-related SF loss in human skeletal muscle using a skinned single muscle fibre model. A large variation in published skinned fibre SF measurements was found to exist in the literature. Therefore, a systematic review and meta-analysis was performed to identify factors causing this variability. The majority of publications were objectively divided into four research groups based on shared authorship. Methodological differences between research groups contributed to ~30% of the variance in the literature, suggesting that they are an important contributor to the variance in published SF values. Different research groups use different activating solutions to study skinned fibres, and were assessed experimentally. Skinned fibres were exposed to different, but commonly used activating solutions (termed A and B). A significantly higher SF and a shorter time to half peak tension (t50) was measured from the same fibres in solution B compared with solution A. The use of TES in solution B instead of Imidazole as a pH buffer largely caused the SF difference, and a lower Cl- concentration and the use of Glutathione in solution B partly caused the faster t50. These findings indicate that the use of different activating solutions likely affects the variance of published SF values. The final study in this thesis compared SF between skinned fibres from physically active and comparatively frail elderly cohorts to a young, healthy group. MHC I fibre SF was significantly higher in solution B than A within all groups. No significant differences in SF, myosin content (SDS PAGE) or order (X-ray diffraction) were observed between groups. These findings suggest that physical activity does not affect age-related skinned fibre SF loss and that SF is related to skinned fibre myosin content.

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Qaisar, Rizwan. "Myonuclear Organization and Regulation of Muscle Contraction in Single Muscle Fibres : Effects of Ageing, Gender, Species, Endocrine Factors and Muscle Size." Doctoral thesis, Uppsala universitet, Klinisk neurofysiologi, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-167723.

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The skeletal muscle fibre is a syncitium where each myonucleus regulates the gene products in a finite volume of cytoplasm i.e., the myonuclear domain (MND). A novel image analysis algorithm applied to confocal images, analyzing MND size and myonuclear spatial distribution in 3-dimensions in single skeletal muscle fibres has been used in this project. The goal was to explore the modulation of myonuclei count and MND size in response to muscle adaptation processes. The effects of ageing, gender, hormones, muscle hypertrophy and body size were investigated on MND size. A strong linear relationship was found between MND size and body size in the muscle fibres from mammals representing a 100,000-fold difference in body size. Independent of species, MND size was highly dependent on MyHC isoform type and mitochondrial contents of skeletal muscle fibres. In hypertrophic mice, a significant effect of MND size on specific force and myosin content was observed. This effect was muscle fibre type-specific and shows that the bigger MNDs in fast-twitch EDL muscle fibres are optimally tuned for force production while smaller MNDs in slow-twitch soleus muscle fibres have a much more dynamic range of hypertrophy without functional compromise. This indicates a critical volume individual myonuclei can support efficiently for a proportional gain in muscle fibre force and size. In human muscle fibres, spatial organization of myonuclei was affected by both ageing and MyHC isoform expression. In fibres expressing type I MyHC isoform, an increased MND size variability and myonuclear aggregates were observed in old age although average MND size was unchanged. In contrast, in type IIa fibres, the average MND size was smaller reflecting smaller size of muscle fibres. Those changes may influence the transcriptional activity per myonucleus and/or local cooperatively of myonuclei in a gender and muscle fibre-type specific manner. Finally, hormone replacement therapy was shown to negate menopause-related functional impairment in skeletal muscle fibres. The positive effect on force was due to quantitative effect in fibres expressing fast myosin isoform while the effect was both quantitative and qualitative in fibres expressing slow myosin isoform. The effect on MND size was fibre type dependent and was achieved by significantly reducing domain size in slow- but not the fast-twitch muscle fibres. Together, our data suggest that modulation of myonuclei count and MND size is a mechanism contributing to remodelling of skeletal muscle in muscle adaptation process. These findings should be considered when developing therapeutic approaches towards restoring muscle mass and strength in muscle wasting conditions.

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Küenzi, Erich. "On the effect of 2,3-butanedione monoxime on contractile properties of single frog skeletal muscle fibres /." Bern, 1990. http://www.ub.unibe.ch/content/bibliotheken_sammlungen/sondersammlungen/dissen_bestellformular/index_ger.html.

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Karatzaferi, Christina. "Human muscle fatigue and recovery : relationship between high-energy phosphate turnover and myosin heavy chain isoform expression in single human skeletal muscle fibres." Thesis, Manchester Metropolitan University, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.324541.

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Selvin, David. "Regulation of Myoplasmic Ca2+ During Fatigue in KATP Channel Deficient FDB Muscle Fibres." Thèse, Université d'Ottawa / University of Ottawa, 2013. http://hdl.handle.net/10393/26174.

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It is known that muscles that lack KATP channel activity generate much greater unstimulated [Ca2+]i and force than normal muscles during fatigue. The increase in unstimulated force in KATP channel deficient muscles is abolished by a partial inhibition of L-type Ca2+ channels, suggesting that it is due to a Ca2+ influx through L-type Ca2+ channels and a subsequent increased myoplasmic Ca2+. However, there is also evidence that the increase in resting force is abolished by NAC, a ROS scavenger. The objective of this study was to reconcile these observations by studying the hypothesis that “the increase in resting [Ca2+]i during fatigue in KATP channel deficient muscles starts with an excess Ca2+ influx through L-type Ca2+ channels, followed by an excess ROS production that causes a further increase in resting [Ca2+]i”. To test the hypothesis, single FDB fibres were fatigued with one tetanic contraction/sec for 180 sec. KATP channel deficient fibres were obtained i) by exposing wild type muscle fibers to glibenclamide, a KATP channel blocker and ii) by using fibres from Kir6.2-/- mice, which are null mice for the Kir6.2 gene that encodes for the protein forming the channel pore. Verapamil, a L-type Ca2+ channel blocker, applied at 1 μM, significantly reduced resting [Ca2+]i during fatigue in glibenclamide-exposed wild type fibres. NAC (1 mM) also reduced resting [Ca2+]i in glibenclamide-exposed muscles. The results suggest that the increase in resting [Ca2+]i during fatigue in KATP channel deficient FDB fibres is due to an influx through L-type Ca2+ channels, and an excess ROS production.

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Pilipowicz, Orest J. "Early satellite cell activation on isolated single muscle fibers." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape2/PQDD_0019/MQ53205.pdf.

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Ghent, Heidi. "Fiber Type-specific Desmin Content in Human Single Muscle Fibers." BYU ScholarsArchive, 2006. https://scholarsarchive.byu.edu/etd/381.

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Анотація:

Contractile and cytoskeletal protein concentrations have been shown to differ on the basis of fiber type in whole muscle homogenates. The purpose of this study was to compare the content of the intermediate filament protein, desmin, between type I and type IIa single muscle fibers from a mixed muscle in human subjects. Biopsies were taken from the vastus lateralis of six recreationally active males. Approximately 150 single muscle fibers were dissected from each sample and analyzed using SDS-PAGE to determine myosin heavy chain (MHC) composition. Following identification, muscle fibers were pooled into two groups (MHC I and MHC IIa). Desmin and actin content within the pooled samples was determined via immunoblotting. On average, muscle samples were composed of 51 ± 7 % type I, 2 ± 1% type I/IIa, 27 ± 5% type IIa, 19 ± 4% type IIa/IIx and 1 ± 1% type IIx MHC single fibers. Desmin and actin contents were 40% and 34% higher in type I fibers compared to type IIa fibers, respectively (P < 0.05). However the desmin to actin ratio was similar between pooled type I and IIa single muscle fibers within the vastus lateralis. These data suggest that desmin and actin content is a function of muscle fiber type. These differences in cytoskeletal protein content may have implications for differences in contractile function and eccentric damage characteristics between fiber types.

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Snyder, Heidi Ghent. "Fiber type-specific desmin content in human single muscle fibers /." Diss., CLICK HERE for online access, 2006. http://contentdm.lib.byu.edu/ETD/image/etd1253.pdf.

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Hind, Albadrani. "Optimizing the Approach for Maintaining Single Muscle Fibers in Culture." Thesis, Université d'Ottawa / University of Ottawa, 2014. http://hdl.handle.net/10393/31900.

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The skeletal muscle is a dynamic tissue that has the ability to change and modify itself to fit the level of required activity; a phenomenon called muscle plasticity. Most studies of muscle plasticity are carried out in situ, a condition for which it is difficult to study and discern between the intrinsic properties of skeletal muscle, the myokines released by muscle fibers and the neurotrophic factors released by neurons innervating skeletal muscles that play various roles in the mechanisms of muscle plasticity. Another approach is to study the morphological and contractile properties of single adult muscle fibers under culture conditions for which one can fully control the level of activity and exogenous factors affecting muscle plasticity. However, the survival of single muscle fiber in culture is very low as most fibers degenerated or supercontracted within 5-7 days. The first objective of this study was to optimize fiber survival in culture. The application of chronic stimulation and beta-adrenergic agonists are two major factors that prevent muscle atrophy and loss of force in denervated muscles in situ. So, objective two was to determine if chronically stimulated single fibers in culture also improve fiber survival and contractile characteristic under culture conditions. The third objective was the same for salbutamol, a beta 2-adrenergic agonist. In regard to the optimization of fiber survival, the Minimum Essential Medium (MEM) was a better medium than Dulbecco’s Modified Eagle Medium (DMEM), changing 50% of the culture medium every two days also improved fiber survival compared to changing the medium every day. Interestingly, inhibiting the proliferation of satellite cells with AraC largely improved fiber survival when fibers were kept under resting conditions, but not when they were chronically stimulated. Finally, under conditions in which proliferation of satellite cells was inhibited, the use of a collagen/laminin mixture as adhering substrate to improve fiber adhesion to glass coverslip gave rise to a better fiber survival than Matrigel that contains not only collagen and laminin but several growth factors. The results suggest i) that when satellite cells (or fibroblasts) are allowed to proliferate they appear to contribute to the degeneration of fibers under resting conditions and ii) that the release of myokines by skeletal muscle fibers (or cytokines by other cells) likely play a role in fiber survival. Contrary to the situation in situ, neither the chronic stimulation nor salbutamol improved fiber survival and contractile characteristics of muscle fibers in culture suggesting that some important factors in culture are missing to allow chronic stimulation and salbutamol to reduce muscle atrophy and loss of force.

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Книги з теми "Single muscle fibres"

Blank, Sally. Electrophoretic myosin isoforms of skeletal muscles and single muscle fibers. 1987.

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Swash, Michael. Myology. Oxford University Press, 2015. http://dx.doi.org/10.1093/med/9780199658602.003.0012.

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Diseases of muscle have become better understood by careful clinical observations, resulting in a clinically useful classification of the different groups of disorders e.g. inherited muscular dystrophies such as Duchenne muscular dystrophy, limb-girdle and metabolic myopathies, and myotonic disorders. A number of scientific approaches have determined the directions taken by this evolving classification. Understanding of the anatomy of the motor unit’s distribution in muscle transformed muscle pathology and muscle electrophysiology, and key to these pathological advances was the use of the histochemical technique for identifying myofibrillar ATPase in muscle fibres. This allowed studies of the distribution of fibre types in muscle in many different disorders. The inflammatory muscle diseases have been better understood since recent advances in immunology have characterized the underlying processes. The limb-girdle and childhood myopathies have proven to be heterogeneous, with many different, apparently causative, underlying genetic mutations.

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Stålberg, Erik. Electromyography. Oxford University Press, 2016. http://dx.doi.org/10.1093/med/9780199688395.003.0007.

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Electromyography (EMG) has been used since the 1940s in the diagnosis of neuromuscular disorders. It has particularly developed with the advent of computers and recording equipment with integrated software. This has made methods of analysis fast, robust, and precise, helping to deal with increasing numbers of patients. Indications have changed dynamically over the years, with the development of new EMG methods themselves and complementary methods used in this field for diagnosis such as histochemistry, genetics, and imaging techniques. This chapter focuses mainly on the routine methods based on recordings with concentric or monopolar needle electrodes, but will also briefly review some of the other EMG methods. There is an increasing understanding of the relationship between the generators (muscle fibres) and the recorded signal that helps interpretation of the recordings. The parameters used for quantitation of the EMG signal are discussed. The findings in pathological conditions are discussed and some practical hints on EMG studies given.

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Katirji, Bashar. Case 17. Edited by Bashar Katirji. Oxford University Press, 2018. http://dx.doi.org/10.1093/med/9780190603434.003.0021.

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Myasthenia gravis is a relatively common neuromuscular junction disorder. The diagnosis of myasthenia gravis may be challenging particularly in seronegative patients. This case starts by discussing the diagnostic modalities available to confirm the diagnosis of myasthenia gravis including serum antibodies, the Tensilon test, and the ice pack test. After a detailed discussion of the physiology of neuromuscular transmission, the case emphasizes the role of electrodiagnostic studies in the diagnosis of myasthenic gravis. This includes detailed findings on repetitive nerve stimulation recording distal and proximal muscles as well as single-fiber electromyography jitter studies. Finally, the diagnostic sensitivity of the available tests in myasthenia gravis is compared and a suggested electrodiagnostic strategy for patients with suspected myasthenic gravis is outlined.

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Katirji, Bashar. The Scope of the EMG Examination. Edited by Bashar Katirji. Oxford University Press, 2018. http://dx.doi.org/10.1093/med/9780190603434.003.0001.

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Clinical electromyography (EMG) refers to the diagnostic tool in the electrophysiological evaluation of disorders of peripheral nerve and muscle. This introductory chapter defines the terms of the discipline and its scope. Clinical EMG used in the evaluation of Clinical EMG is utilized by a variety of physicians, including specialists in the field of neurology, physical medicine and rehabilitation, orthopedics, hand surgery, neurosurgery, spine, rheumatology and pain management. The scope of the EMG Examination includes nerve conduction studies and needle EMG. It also includes other specialized testing such as late responses, repetitive nerve stimulation and single fiber EMG. This chapter discusses the referral process to the EMG laboratory and guides the readers to the best practice in the EMG evaluation of patients with neuromuscular disease. Special attention to testing young children and testing patients in the intensive care unit is given. The generation, format and final layout of the EMG report is also advised.

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Частини книг з теми "Single muscle fibres"

Collins, Charlotte A., and Peter S. Zammit. "Isolation and Grafting of Single Muscle Fibres." In Methods in Molecular Biology, 319–30. Totowa, NJ: Humana Press, 2009. http://dx.doi.org/10.1007/978-1-59745-060-7_20.

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Ashley, C. C., T. J. Lea, I. P. Mulligan, R. E. Palmer, and S. J. Simnett. "Activation and Relaxation Mechanisms in Single Muscle Fibres." In Mechanism of Myofilament Sliding in Muscle Contraction, 97–115. Boston, MA: Springer US, 1993. http://dx.doi.org/10.1007/978-1-4615-2872-2_9.

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Yu, Leepo C., and Richard J. Podolsky. "Equatorial X-ray Diffraction Studies of Single Skinned Muscle Fibres." In Molecular Mechanisms in Muscular Contraction, 265–86. London: Macmillan Education UK, 1990. http://dx.doi.org/10.1007/978-1-349-09814-9_9.

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Griffiths, P. J., C. C. Ashley, M. A. Bagni, G. Cecchi, and Y. Maèda. "Time-Resolved Equatorial X-Ray Diffraction Measurements in Single Intact Muscle Fibres." In Mechanism of Myofilament Sliding in Muscle Contraction, 409–22. Boston, MA: Springer US, 1993. http://dx.doi.org/10.1007/978-1-4615-2872-2_38.

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Lännergren, Jan, and Joseph D. Bruton. "Mitochondrial Ca2+ in Mouse Soleus Single Muscle Fibres in Response to Repeated Tetanic Contractions." In Advances in Experimental Medicine and Biology, 557–62. Boston, MA: Springer US, 2003. http://dx.doi.org/10.1007/978-1-4419-9029-7_49.

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Fujino, M., T. Arima, C. Hasegawa, K. Harano, M. Takahashi, S. Sano, and S. Fujino. "The Surface Input Site Responsible for Excitation-Contraction (E-C) Coupling Mechanism in Single Skeletal Muscle Fibres of Frog." In Excitation-Contraction Coupling in Skeletal, Cardiac, and Smooth Muscle, 431–32. Boston, MA: Springer US, 1992. http://dx.doi.org/10.1007/978-1-4615-3362-7_67.

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Reconditi, Massimo, Ian Dobbie, Malcolm Irving, Olivier Diat, Peter Boesecke, Marco Linari, Gabriella Piazzesi, and Vincenzo Lombardi. "Myosin Head Movements during Isometric Contraction Studied by X-Ray Diffraction of Single Frog Muscle Fibres." In Advances in Experimental Medicine and Biology, 265–70. Boston, MA: Springer US, 1998. http://dx.doi.org/10.1007/978-1-4684-6039-1_31.

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Stienen, G. J. M., J. Lännergren, and G. Elzinga. "ATPase activity of intact single muscle fibres of Xenopus laevis is related to the rate of force redevelopment after rapid shortening." In Cardiac Energetics, 111–17. Heidelberg: Steinkopff, 1987. http://dx.doi.org/10.1007/978-3-662-11289-2_11.

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Termin, A., R. S. Staron, and D. Pette. "Myosin Heavy Chain Isoforms in Single Fibers of Transforming Rat Muscle." In The Dynamic State of Muscle Fibers, edited by Dirk Pette, 463–72. Berlin, Boston: De Gruyter, 1990. http://dx.doi.org/10.1515/9783110884784-037.

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Di Foggia, Valentina, and Lesley Robson. "Isolation of Satellite Cells from Single Muscle Fibers from Young, Aged, or Dystrophic Muscles." In Methods in Molecular Biology, 3–14. Totowa, NJ: Humana Press, 2012. http://dx.doi.org/10.1007/978-1-61779-980-8_1.

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Тези доповідей конференцій з теми "Single muscle fibres"

Chinnam, Krishna Chytanya, Federico Fabriani, Iucci Giovanna, and Giulia Lanzara. "Electrospun PVDF Miniaturized Muscles for Bio Inspired Morphing Materials." In ASME 2018 Conference on Smart Materials, Adaptive Structures and Intelligent Systems. American Society of Mechanical Engineers, 2018. http://dx.doi.org/10.1115/smasis2018-8054.

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Several biological creatures represent a great inspiration for the realization of advanced morphing materials. For instance, bat wing is extremely interesting because of its unique ability of drastically changing shape and size thanks to an embedded distributed array of ultra-small-in-size muscles. This is obviously done as a response to continuously detected external stimuli. Novel ultra-lightweight and non-invasive artificial muscles that can exploit a dual functionality and that can be integrated into hosting materials, are here investigated. The muscles are made of a piezoelectric (PVDF) single micro-fibre and a micro-fibre rope created using a simple electrospinning technique. The advantage of this technique is the less-complex in-situ fibres poling during electrospinning which makes them an attractive alternative compared to thin PVDF films that require an additional complicated poling step to achieve their piezoelectric properties. Muscles that possess an active and passive electromechanical response based on a ∼ 3-micron thick single PVDF fibre and ∼ 150-micron thick PVDF fibred rope, were realized. Preliminary results prove that these PVDF fibres have a highly accurate electromechanical response over an extremely wide frequency range. Fully constrained single fibres and fibre ropes, when actuated with the corresponding electric fields, show a midpoint displacement of ∼ 36 μm.

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Zhang, Chi, and Yingxin Gao. "Finite Element Analysis of Force Transmission in Skeletal Muscle Fiber." In ASME 2012 Summer Bioengineering Conference. American Society of Mechanical Engineers, 2012. http://dx.doi.org/10.1115/sbc2012-80670.

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Skeletal muscle has a complex hierarchical structure which is mainly composed of myofibers and the surrounding extracellular matrix (ECM) including endomysium, perimysium, and epimysium. To produce movement, force generated by individual myofibers has to be transmitted to the tendon. Previous studies have shown that many muscle fibers terminate within the fascicle without reaching either ends of the tendon[1,2], in which case force generated has to be transmitted laterally through the ECM to surrounding fibers and then to the tendon[3]. In this study, a two dimensional finite element (FE) model of a single muscle fiber was developed to determine the effects of ECM stiffness and tapered end angles of myofiber on lateral transmission of force in skeletal muscle.

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Manal, Kurt, and Thomas S. Buchanan. "A Numerical Method for Estimating Tendon Slack Length." In ASME 2003 International Mechanical Engineering Congress and Exposition. ASMEDC, 2003. http://dx.doi.org/10.1115/imece2003-43084.

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Forces generated by muscle are transferred to bone via tendon. Since muscle force cannot be measured directly, computer modeling is a useful tool to enhance our understanding of normal and pathological movement. Hill-type muscle models have been used to estimate force based on information about a muscle’s architecture, activation and kinematics (Delp et al., 1995; Manal et al., 2002). Architectural parameters include optimal fiber length (lom), tendon slack length (lst), pennation angle (α), and maximum isometric force (Fmax). In addition, musculotendon length (lmt) and activation (a) are required inputs when estimating isometric muscle force (Equation I). Fm=f(lmt,lom,lst,Fmax,α,a)(1) Musculotendon length can be determined from MR images (Arnold et al., 2000), and activation recorded from EMGs (Manal, et al., 2002). Optimal fiber length and pennation angle can be measured experimentally (Murray, 2002), while Fmax can be estimated from the muscle’s physiologic cross-sectional area. Tendon slack length however cannot be measured readily, and therefore few estimates of lst can be found in the literature. In this paper we present a numerical method for estimating tendon slack from subject specific muscle parameters and musculotendon lengths. An advantage of this method is that it yields subject specific estimates of tendon slack length.

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Bryant, Matthew, Michael A. Meller, and Ephrahim Garcia. "Toward Variable Recruitment Fluidic Artificial Muscles." In ASME 2013 Conference on Smart Materials, Adaptive Structures and Intelligent Systems. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/smasis2013-3136.

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We investigate taking advantage of the lightweight, compliant nature of fluidic artificial muscles to create variable recruitment actuators in the form of artificial muscle bundles. Several actuator elements at different diameter scales are packaged to act as a single actuator device. The actuator elements of the bundle can be connected to the fluidic control circuit so that different groups of actuator elements, much like individual muscle fibers, can be activated independently depending on the required force output and motion. This novel actuation concept allows us to save energy by effectively selecting the size of the actuators on the fly based on the instantaneous required load, versus the traditional method wherein actuators are sized for the maximum required load, and energy is wasted by oversized actuators most of the time. This design also allows a single bundled actuator to operate in substantially different force regimes, which could be valuable for robots that need to perform a wide variety of tasks and interact safely with humans. This paper will propose this actuator concept and show preliminary results of the design, fabrication, and experimental characterization of three such bioinspired variable recruitment actuator prototypes.

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Adams, Corinne R., Mark A. Baldwin, Peter J. Laz, Paul J. Rullkoetter, and Joseph E. Langenderfer. "Development of a Computational Model to Study Effects of Rotator Cuff Tear Size and Location on Muscle Moment Arms." In ASME 2007 Summer Bioengineering Conference. American Society of Mechanical Engineers, 2007. http://dx.doi.org/10.1115/sbc2007-176401.

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Rotator cuff tendon tear causes alterations to cuff muscle architecture and tendons including muscle fascicle contracture and increased tendon length, fatty infiltration of the muscle fibers, muscle fiber pennation angle changes, asymmetric muscle atrophy, and altered muscle fiber type composition, e.g. [1]. These changes ultimately result in a reduction in muscle force, and frequently lead to a reduction of shoulder strength and a loss of functionality. Recently, division of the cuff tendons in a manner related to cuff tear has been shown to alter tendon excursions and cause muscle moment arms reductions in a cadaver experiment [2] and a computational study [3]. Evaluations of the effects of cuff tear size and location on cuff muscle moment arms have not been conducted. Consequently, the mechanisms by which the muscle force and moment arm changes affect joint strength are not well understood. An improved understanding of these relationships would increase potential for rehabilitation of joint strength following cuff repair. Models for evaluating rotator cuff tear are non-existent since subject-specific models have focused on healthy normal shoulders. Consequently, models have not been used to quantify the effects of clinically observed changes in muscle and tendon architecture on muscle moment arm and force generating capacity.

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Shafer, Michael W., Heidi P. Feigenbaum, and Diego Ricardo Higueras Ruiz. "A Novel Biomimetic Torsional Actuator Design Using Twisted Polymer Actuators." In ASME 2017 Conference on Smart Materials, Adaptive Structures and Intelligent Systems. American Society of Mechanical Engineers, 2017. http://dx.doi.org/10.1115/smasis2017-3803.

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Artificial muscle systems have the potential to impact many technologies ranging from advanced prosthesis to miniature robotics. Recently, it has been shown that twisting drawn polymer monofilaments, such as nylon fishing line or sewing thread, can result in a biomimetic thermally activated torsional actuator. The actuation phenomenon in these twisted polymer actuators (TPAs) is thought to be a result of an untwisting that occurs about the fiber’s axis due to an anisotropic thermal expansion. Before being twisted, the precursor fibers are comprised of polymer chains that are aligned axially. During fabrication of TPAs, the polymer chains reorient as the precursor fiber is twisted about the central axis of the monofilament. At the end of the fabrication process, the TPA is annealed in order to relieve internal stresses and to keep the fiber in the twisted configuration. The mechanism of untwisting actuation is generally thought to be a result of radial expansion and axial contraction. After being twisted, these radial and axial expansion relationships remain relatively unchanged, but the polymer chain direction is no longer axially aligned. Thus, upon heating the twisted fibers of the TPA, the fibers untwist and torsional actuation occurs. This actuation phenomenon has been used in the past to create linear actuators, but can also be use directly as a torsional actuator. Compared to other torsional actuators TPAs are low cost, lightweight, and can actuate reasonably high torques per unit volume. However, because TPAs are thermally activated, they may not be suitable for all applications. In this work, we present a novel TPA design for use as a torsional actuator for miniature actuation and artificial muscle applications. Our design bundles twisted monofilaments to increase the torque. Both fabrication and testing methods of the new design are presented. Results for temperature versus torsional displacement under various loads give insights as to how these actuators may be used and the reversibility of the actuation process under different fabrication loads. Additionally, comparisons are made between these bundled actuators and similarly loaded single TPA monofilament actuation.

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Baker, Brendon M., Nandan L. Nerurkar, Jason A. Burdick, Dawn M. Elliott, and Robert L. Mauck. "Fabrication and Modeling of an Electrospun Tri-Polymer Composite for the Engineering of Fibrous Tissues." In ASME 2008 Summer Bioengineering Conference. American Society of Mechanical Engineers, 2008. http://dx.doi.org/10.1115/sbc2008-193174.

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Aligned, electrospun scaffolds are a useful tool for the engineering of fiber-reinforced tissues (such as tendon, meniscus, and muscle) as they mimic the topography and anisotropy of the native tissue extracellular matrix (ECM) [1]. We have shown that fiber-alignment of slow-degrading poly(ε-caprolactone) (PCL) enhances the organization of newly-formed ECM and improves construct properties [2]. However, one significant drawback to these 3D templates is their small pore size, resulting from tight fiber packing, which hampers cell infiltration. To increase scaffold porosity and thereby accelerate cell ingress, we have recently reported on the fabrication of dual polymer composite scaffolds containing both water-soluble poly(ethylene oxide) (PEO) and PCL fibers [3]. Removal of the sacrificial PEO fibers before seeding improved cell infiltration, but did so at the cost of the overall structural integrity. To further expand the potential properties (mechanics and degradation) of these composite scaffolds, this study introduced a third component (50:50 poly(lactic-co-glycolic acid) (PLGA)) using a newly constructed tri-polymer electrospinning device. We evaluated each polymer singly and when combined into a tri-polymer (3P) fibrous network. To better understand the mechanical response of these composites, we used a hyperelastic, constrained mixture model to assess and predict the response of these composite nanofibrous meshes for a range of compositions.

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Spath, William E., and Wayne W. Walter. "Development of a Two-Dimensional Model of the Human Arm to Investigate the Biomimetic Substitution of Human Bicep Muscle With a Dielectric Electroactive Polymer Muscle Actuator." In ASME 2012 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2012. http://dx.doi.org/10.1115/imece2012-85686.

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Current prostheses are not able to meet the needs of patients. The authors have recently been investigating the feasibility of integrating multiple types of electroactive polymers (EAP) to develop an artificial muscle for prostheses and muscle implants; much like biological muscle is made up of multiple types of muscle fibers. The intent is to produce a lightweight device which has smooth fluid-like motion, in contrast to the jerky motion of current prostheses which use heavy rotary actuators. A human arm model, isolating the bicep muscle, was developed to better understand the requirements on force and strain that an artificial muscle must meet to replace biological muscle. This study was conducted with the assistance of orthopedic surgeons from the Rochester General Hospital. Bicep muscle characteristics were compared with those of dielectric elastomer electroactive polymers (DEAP), since they produce relatively high force and large strain during actuation. Results show that current characteristics of DEAPs will not allow for direct substitution of human muscle fibers with EAPs because their force and strain outputs are too low. To increase the force and strain output of DEAPs to that of human muscle fibers, the stiffness of the DEAP needs to be increased. The analysis done and results obtained are discussed in the paper, as well as possible ways to increase the stiffness of EAPs to better meet the requirements for biological muscle replacement.

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Wang, James H. C., and Frank C. P. Yin. "Contractility Affects Stress Fiber Remodeling and Reorientation of the Endothelial Cells in Response to Mechanical Stretching." In ASME 1999 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 1999. http://dx.doi.org/10.1115/imece1999-0406.

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Abstract Actin cytoskeletal stress fibers are thought to be the major cellular constituents responsible for cell shape and locomotion. As such, stress fiber remodeling likely plays a major role in the cell reorientation responses to mechanical stimuli (Iba and Sumpio, 1991). The assembly and dis-assembly of stress fibers in non-muscle cells are mediated by contractility via the interaction of actin and myosin (Chrzanowska-Wodnicka and Burridge, 1996). Reactive oxygen species (ROS) also play an important role in organization of stress fibers (Hinshaw et al., 1991). Since cyclic stretching can enhance production of certain ROS, including H2O2 (Howard et al., 1997) and H2O2 stimulates, in a time- and dose-dependent manner, myosin light chain (MLC) phosphorylation (Zhao and Davis, 1998), stress fiber remodeling and cell reorientation in response to cyclic stretching should be affected by changes in contractility — including changes in ROS. The roles of these factors have not been carefully examined.

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Saharan, Lokesh, and Yonas Tadesse. "Fabrication Parameters and Performance Relationship of Twisted and Coiled Polymer Muscles." In ASME 2016 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2016. http://dx.doi.org/10.1115/imece2016-67314.

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Twisted and Coiled Polymer (TCP) muscles are soft actuators made by inserting twist in a precursor fiber while attaching a dead weight at the end, followed by heat treatment. TCP muscles are thermally driven actuators with high power to weight ratio, large strain and low cost. These muscles have a wide variety of applications in engineering, specifically for robotics since these actuators have large linear deformation in response to applied power (Joule’s Effect). The performance of these muscles depend on numerous fabrication parameters such as speed of the coiling, dead weight used, precursor fiber type, number of filament in precursor fiber, number of plies and training cycles. An in-depth study of the fabrication parameters is required to understand the performance of the muscles. We have designed experimental setup to study the performance of the muscles on different input parameters such as load, current, voltage and output results such as displacement, force and temperature. We present the study of single, double and tripled plied muscles that are fabricated by plying together a twisted and coiled filament. Further, the power consumption of the muscles under various conditions is discussed. This study would help to establish a procedure to fabricate these materials with consistent properties.

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Звіти організацій з теми "Single muscle fibres"

Goeckeritz, Joel, Nathan Schank, Ryan L Wood, Beverly L Roeder, and Alonzo D Cook. Use of Urinary Bladder Matrix Conduits in a Rat Model of Sciatic Nerve Regeneration after Nerve Transection Injury. Science Repository, December 2022. http://dx.doi.org/10.31487/j.rgm.2022.03.01.

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Previous research has demonstrated the use of single-channel porcine-derived urinary bladder matrix (UBM) conduits in segmental-loss, peripheral nerve repairs as comparable to criterion-standard nerve autografts. This study aimed to replicate and expand upon this research with additional novel UBM conduits and coupled therapies. Fifty-four Wistar Albino rats were divided into 6 groups, and each underwent a surgical neurectomy to remove a 7-millimeter section of the sciatic nerve. Bridging of this nerve gap and treatment for each group was as follows: i) reverse autograft—the segmented nerve was reversed 180 degrees and used to reconnect the proximal and distal nerve stumps; ii) the nerve gap was bridged via a silicone conduit; iii) a single-channel UBM conduit; iv) a multi-channel UBM conduit; v) a single-channel UBM conduit identical to group 3 coupled with fortnightly transcutaneous electrical nerve stimulation (TENS); vi) or, a multi-channel UBM conduit identical to group 4 coupled with fortnightly TENS. The extent of nerve recovery was assessed by behavioural parameters: foot fault asymmetry scoring measured weekly for six weeks; electrophysiological parameters: compound muscle action potential (CMAP) amplitudes, measured at weeks 0 and 6; and morphological parameters: total fascicle areas, myelinated fiber counts, fiber densities, and fiber sizes measured at week 6. All the above parameters demonstrated recovery of the test groups (3-6) as being either comparable or less than that of reverse autograft, but none were shown to outperform reverse autograft. As such, UBM conduits may yet prove to be an effective treatment to repair relatively short segmental peripheral nerve injuries, but further research is required to demonstrate greater efficacy over nerve autografts.

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