The biology of long-term denervated skeletal muscle

This review concentrates on the biology of long-term denervated muscle, especially as it relates to newer techniques for restoring functional mass. After denervation, muscle passes through three stages: 1) immediate loss of voluntary function and rapid loss of mass, 2) increasing atrophy and loss of sarcomeric organization, and 3) muscle fiber degeneration and replacement of muscle by fibrous connective tissue and fat. Parallel to the overall program of atrophy and degeneration is the proliferation and activation of satellite cells, and the appearance of neomyogenesis within the denervated muscle. Techniques such as functional electrical stimulation take advantage of this capability to restore functional mass to a denervated muscle

Contractile properties of standard and nerve-intact muscle grafts in the rat

The contractile properties of standard and nerve-intact grafts of extensor digitorum longus muscles of rats were compared in vitro. Fourteen days after grafting, the time to peak tension and the half-relaxation times of nerve-intact grafts were shorter than those of standard grafts, but both were longer than control values. By 60 days, these variables attained normal values. At every sample period, the tetanic tensions of nerve-intact grafts were higher than those of standard grafts. Even at the early sampling periods, the twitch-tetanic tension ratios of nerve-intact grafts were close to normal values, whereas those of standard grafts were higher than normal. Stabilized nerve-intact grafts had a larger mass and greater maximum tetanic tension development than standard grafts, but were more fatigable. Compared with control EDL muscles, stable nerve-intact grafts show no differences except for lessened fatigability, whereas standard grafts demonstrate significant functional deficits.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/50136/1/880080511_ftp.pd

Genetic regulatory pathways of split‐hand/foot malformation

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/146859/1/cge13434-sup-0001-EditorialProcess.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/146859/2/cge13434_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/146859/3/cge13434.pd

Regeneration from short stumps of the rat gastrocnemius muscle

Nachweis der Regeneration eines neun Muskels nach Entfernung des ganzen Gastrocnemius-Muskels der Ratte bis auf einem 3–4 mm langen Stump. Nur bei vorhandener Verbindung zwischen der regenerierenden Achilles-Sehne und dem proximalen Muskelstumpf kommt es zu bedeutender Verlängerung des proximalen Rests des Muskels.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/42589/1/18_2005_Article_BF01934825.pd

Interconnectedness of anatomy

No abstract.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/34283/1/1_ftp.pd

Muscle morphogenesis in axolotl limb regenerates after removal of stump musculature

This research was designed to determine whether or not a normal stump musculature is required for normal morphogenesis of muscle within the regenerating amphibian limb. Limbs of adult axolotls were amputated proximal to the elbow, and approximately 99% of the skeletal muscle was removed from the limb stump. The early stages of regeneration and blastema formation followed a relatively normal morphological and temporal course. In all cases grossly normal limbs regenerated. These regenerated limbs all contained large amounts of muscle, which was usually arranged into anatomically recognizable muscles in both the forearm and hand. It is concluded that muscle morphogenesis in the regenerating amphibian limb is not dependent upon an anatomically normal stump musculature.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/34079/1/0000358.pd

The regeneration of axolotl limbs covered by frog skin

Forearm skin of Stage XXIV Rana pipiens, which cannot regenerate limbs, was removed and placed upon the skinned forearms of young axolotls. The axolotl limbs were amputated immediately through the level of the grafts. Frog epidermis migrated to cover the amputation surface. Dedifferentiation and early blastema formation occurred beneath the frog wound epidermis. Limb regeneration continued, but in time axolotl epidermis overgrew the frog epidermis. The experiment shows that epidermis from nonregenerating frog limbs is still capable of supporting typical epimorphic regeneration.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/24024/1/0000273.pd

Muscle regeneration in amphibians and mammals: Passing the torch

Skeletal muscle in both amphibians and mammals possesses a high regenerative capacity. In amphibians, a muscle can regenerate in two distinct ways: as a tissue component of an entire regenerating limb (epimorphic regeneration) or as an isolated entity (tissue regeneration). In the absence of epimorphic regenerative ability, mammals can regenerate muscles only by the tissue mode. This review focuses principally on the regeneration of entire muscles and covers what is known and what remains to be elucidated about fundamental mechanisms underlying muscle regeneration at this level. Developmental Dynamics 226:167–181, 2003. © 2003 Wiley-Liss, Inc.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/35172/1/10223_ftp.pd

Clouston syndrome with dental anomalies, micropores of hair shafts and absence of palmoplantar keratoderma

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/154514/1/jde15236.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/154514/2/jde15236_am.pd

Muscle fiber branching -- difference between grafts in old and young rats

Large numbers of branched muscle fibers occur in the freely grafted rat extensor digitorum longus muscle. The ratio of branched/non-branched muscle fibers in grafts is much higher in old (24 months) than in young (4 months) host rats. Cross-age transplants show that the proportion of branched muscle fibers is related to the age of the grafted muscle and not to the age of the host. This is in contrast to mass and maximum isometric tension, in which the age of the host, rather than the age of the grafted muscle, is the determinant of the success of the muscle graft.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/29138/1/0000179.pd