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At least 451 records · Page 25Linked to original sources
PubMed1999

Surgical treatment of paralysis of the inferior division of the oculomotor nerve.

BACKGROUND: Paralysis of the inferior division of the oculomotor nerve is relatively rare. Little has been written about its surgical treatment. METHODS: Five patients with paralysis of the inferior division of the oculomotor nerve were treated with transposition of the superior rectus muscle toward the insertion of the medial rectus muscle, transposition of the lateral rectus muscle toward the insertion of the inferior rectus muscle, and tenotomy of the superior oblique tendon in the affected eye. RESULTS: All 5 patients had a satisfactory outcome. They were free of diplopia in the primary position as of their last examination. Follow-up ranged from 3 to 10 years after surgery. CONCLUSION: Paralysis of the inferior division of the oculomotor nerve can be adequately treated by simultaneous transposition of the superior rectus muscle toward the insertion of the medial rectus muscle, transposition of the lateral rectus muscle toward the insertion of the inferior rectus muscle, and tenotomy of the superior oblique tendon in the affected eye.

Adult↗
PubMed1986

The anterior scalene muscle in thoracic outlet compression syndrome. Histochemical and morphometric studies.

Histochemical studies and morphometric fiber type analysis were done on biopsy specimens of anterior scalene muscle (ASM) from patients with thoracic outlet compression syndrome (TOS), without structural abnormality. Hypertrophy and atrophy factors were determined from muscle fiber histograms of ASM from controls, patients with TOS, and after scalene tenotomy. Scalene muscle from patients with TOS showed marked type 1 (tonic contracting) fiber predominance (85.1% +/- 5.1%) and type 1 fiber hypertrophy (55.6 +/- 2.7 microns). After tenotomy there is a reduction of type 1 fiber representation, selective atrophy in the type 1 fiber system (atrophy factor, 0.66 +/- 0.24), and increase of type 2 fibers. These distinctive changes indicate that ASM is uniquely structured in fiber composition to sustain prolonged contraction. The ASM in patients with TOS demonstrates an extraordinary adaptive transformation and recruitment response in the type 1 fiber system reflecting chronic increased tone or motor neuron stimulation. These observations form a basis for clarifying the structural and pathophysiologic changes in TOS.

Adult↗
PubMed1988

Responses of diseased muscle to electrical and mechanical intervention.

It is well established that the properties of muscle fibres are influenced by their neurons and that this is at least in part mediated by the pattern of activity. Application of this knowledge has led to the experimental trial of electrical stimulation in diseased muscle, both in the dystrophic mouse and in children with Duchenne muscular dystrophy. This has shown a beneficial effect of slow frequency stimulation. Another route through which muscle properties can be influenced is by changing the load by procedures such as tenotomy. This has been studied by complete tenotomy in normal animals and recently by selective partial procedures in human disease. Y. Rideau has shown that release of early shortening (contractures) of several muscles, a consistent feature in Duchenne muscular dystrophy, has a beneficial effect on muscle function. From personal observations on a number of Rideau's patients who have undergone this procedure the improvement in function seems disproportionate to what could be explained on simple biomechanical grounds alone and suggests some more fundamental change in the contractile properties of the muscle.

Electric Stimulation↗
PubMed1983

Properties of soleus muscle Z-lines and induced Z-line analogs revealed by dissection with Ca2+-activated neutral protease.

Rat soleus muscle Z-lines and Z-line anomalies induced by neostigmine methyl sulfate (NMS) and cat soleus muscle Z-lines and Z-line anomalies induced by tenotomy were examined by electron microscopy before and after dissection of muscle fibers with Ca2+-activated neutral protease (CAF) to elucidate structural properties of Z-lines and related Z-line-type structures. In both normal and treated muscles, interdigitation of thin (6-7 nm) filaments, which were continuous with I-filaments (actin) from adjacent sarcomeres, was observed at the Z-line in longitudinal section. Both neostigmine methyl sulfate and tenotomy treatments induced muscle atrophy associated with Z-line degradation, streaming, and irregular distribution and accumulation of Z-line material and Z-rod formation. Tenotomized muscle also was characterized by the presence of N-line-like bands and I-Z-I brushes. CAF digestion removed the electron-dense covering material from Z-rods and revealed a backbone of actin filaments. The origin of Z-rods, their structural similarity to Z-lines in longitudinal and cross section, and their susceptibility to CAF indicate that Z-rods are directly related to native Z-lines and are probably lateral polymers of a basic Z-line unit. The regular square net alignment (22 nm) of I-filaments (actin) in cross sections of I-Z-I brushes which contain no N-lines suggests that the I-square net arrangement near the Z-line is determined by Z-filament-actin filament interaction rather than by the N-line or other factors. The results suggest that I-filaments (actin) penetrate the mammalian Z-line and are Z-line constituents and that the width of Z-lines and the length of Z-rods are determined by the amount of overlap of actin filaments. The perpendicular periodicity of Z-rods and the zigzag-oblique arrowheadlike appearance seen in longitudinal sections of Z-lines are attributed to alpha-actinin.

Animals↗
PubMed1994

Satellite cells in slow and fast rat muscles differ in respect to acetylcholinesterase regulation mechanisms they convey to their descendant myofibers during regeneration.

The hypothesis of satellite cell diversity in slow and fast mammalian muscles was tested by examining acetylcholinesterase (AChE) regulation in muscles regenerating 1) under conditions of muscle disuse (tenotomy, leg immobilization) in which the pattern of neural stimulation is changed, and 2) after cross-transplantation when the regenerating muscle develops under a foreign neural stimulation pattern. Soleus (SOL) and extensor digitorum longus (EDL) muscles of the rat were allowed to regenerate after ischemic-toxic injury either in their own sites or had been cross-transplanted to the site of the other muscle. Molecular forms of AChE in regenerating muscles were analyzed by velocity sedimentation in linear sucrose gradients. Neither tenotomy nor limb immobilization significantly affected the characteristic pattern of AChE molecular forms in regenerating SOL muscles, suggesting that the neural stimulation pattern is probably not decisive for its induction. During an early phase of regeneration, the general pattern of AChE molecular forms in the cross-transplanted regenerating muscle was predominantly determined by the type of its muscle of origin, and much less by the innervating nerve which exerted only a modest modifying effect. However, alkali-resistant myofibrillar ATPase activity on which the separation of muscle fibers into type I and type II is based, was determined predominantly by the motor nerve innervating the regenerating muscle. Mature regenerated EDL muscles (13 weeks after injury) which had been innervated by the SOL nerve became virtually indistinguishable from the SOL muscles in regard to their pattern of AChE molecular forms. However, AChE patterns of mature regenerated SOL muscles that had been innervated by the EDL nerve still displayed some features of the SOL pattern. In regard to AChE regulation, muscle satellite cells from slow or fast rat muscles convey to their descendant myotubes the information shifting their initial development in the direction of either slow or fast muscle, respectively. The satellite cells in fast or slow muscles are, therefore, intrinsically different. Intrinsic information is expressed mostly during an early phase of regeneration whereas later on the regulatory influence of the motor nerve more or less predominates.

Acetylcholinesterase↗
PubMed2006

Pulsed ultrasound treatment accelerates the repair of Achilles tendon rupture in rats.

A rat tenotomy model was used to investigate the effect of combined conservative management and pulsed ultrasound (PUS) on the repair of tenotomized Achilles tendon. Hemitenotomy of right medial Achilles tendon was performed in 48 rats without suture, and patella tenotomy was performed to mimic immobilization and limb disuse of an injured limb. PUS and sham PUS were applied to the healing wound for the treatment group and control group for 5 min, 3 times per week for 2 or 4 weeks, respectively. Tensile tests showed that the ultimate tensile strength (UTS) and stiffness of the repaired tendon in the treatment group at 2 weeks reached 48.92+/-8.39% and 62.48+/-32.46% of the contralateral normal tendon strength, which were significantly higher than those of the control group (UTS, 30.36+/-15.46%; stiffness, 33.90+/-17.59; p<0.05). At 4 weeks, UTS increased to 77.09+/-15.31% and stiffness to 92.48+/-31.12% in the treatment group, significantly higher than those in the control group (UTS, 54.33+/-18.40%, p<0.01; stiffness, 65.02+/-25.48%, p<0.05). Light microscopy revealed more regular, denser, and better aligned collagen fibers in the healing scar of the PUS-treated healing tendons. The findings suggested that PUS were able to accelerate the healing of the ruptured tendons.

Achilles Tendon↗
PubMedDate not supplied

Recovery from central core degeneration of the tenotomized rat soleus muscle.

The soleus muscle of the rat undergoes degenerative changes after tenotomy. The effects are maximal one week postoperatively, after which follows a period of recovery. Muscle histology eventually returns to normal six week after tenotomy. Recovery is effected by means of peripheral myofibril splitting and de novo synthesis of myofibrils within the central portion of the fiber.

Animals↗
PubMed1984

Changes in fiber type composition in growing muscle as a result of dynamic exercise and static overload.

The effects of dynamic exercise (jumping) and static overload (synergist tenotomy) on rat soleus muscle were investigated during a growing phase in juvenile animals. The relative proportions of slow twitch (type 1), fast twitch (type 2a) and intermediate (type 2c) fibers were determined histochemically. The control animals, as part developmental process, lost type 2a fibers apparently by conversion to type 1 fibers via the type 2c form. Synergist tenotomy enhanced the conversion of type 2a fibers to type 2c fibers as these muscles displayed fewer type 2a fibers than control animals at the same age. In contrast, the dynamic exercise delayed the loss of type 2a fibers from the soleus. When the two exercises were combined the effects on fiber type proportions cancelled each other; this group also had a large number of type 2c fibers. This present study indicates that the activity imposed on a muscle influences the maturational development of the constituent fiber types.

Animals↗
PubMed1983

The effect of diphosphonates on heterotopic ossification in regenerating Achilles tendon of the mouse.

Midpoint tenotomy of the mouse Achilles tendon is followed by regeneration with heterotopic ossification at the junction of tendon stump and the regenerated segment. This heterotopic bone formation occurs through a process of endochondral ossification and the cartilage cells appear to arise by a process of fibroblast transformation. Five weeks after tenotomy 60 per cent. of specimens show cartilage and bone formation whilst the remaining 40 per cent. show chondrification only. After 10 weeks all specimens showed bone formation with trabecular bone and haemopoietic marrow. The treatment of tenotomised animals with either disodium ethane-1, 1-diphosphonate (EHDP) or disodium dichloromethylene diphosphonate (Cl2MDP) has no effect on the process of heterotopic ossification which can be detected at the radiological or light microscopical level.

Achilles Tendon↗
PubMed1993

Factors responsible for the development of avascular necrosis secondary to the treatment of congenital dislocation of the hip.

We present 104 cases of unilateral congenital dislocation of the hip treated with the same regime between 1977 and 1988. The patients had an average age of 12 months (range 4-24). The average age at follow-up was 6 years (range 3-13). The incidence of avascular necrosis was 37%. Avascular necrosis presented most frequently in babies of 7 months at the start of treatment, in Tonnis type IV when an adductor tenotomy was not performed, and after open reductions. The most influential factor was the absence of the femoral head descent at the end of the period of traction. The "effective" prereduction traction and the performance of an adductor tenotomy when necessary were the principle factors in avoiding avascular necrosis.

Child↗
PubMed1975

Satellite cells of the rat soleus muscle in the process of compensatory hypertrophy combined with denervation.

Compensatory hypertrophy was induced in the rat soleus muscle by sectioning the tendon of the ipsilateral gastrocnemius and plantaris muscle. Seven days after tenotomy of synergistic muscles, when soleus hypertrophy attains about 40%, the number of satellite cells (expressed as percentage of all muscle nuclei found in the same cross-sections) as revealed by electron microscopy, was increased from 5.8+/-0.06% in the normal soleus muscle to 16.6+/-1.26%. After four days' denervation of the soleus muscle the percentage of satellite cells was increased to 7.2+/-0.62%. In experiments where hypertrophy of the soleus muscle was combined with denervation three days after tenotomy of synergists, and examined after another four days (during which time it loses, as has previously been shown, over 40% of its predenervation weight), the number of satellite cells was greatly increased to 29.9+/-3.42%. This increase is apparently due to two independent processes which take place during the first postoperative period: a) mitotic division of satellite cells during the early stages of compensatory hypertrophy and b) pinching off of muscle nuclei from rapidly atrophying muscle fibres due to subsequent denervation. Activation of satellite cells was mainly manifested by expansion of smooth and especially of rough endoplasmic reticulum, a rich Golgi complex, high pinocytotic activity, increased number of ribosomes and by nuclear changes. Concomitantly with the increased number of satellite cells, proliferation of fibroblasts, macrophages and mast cells could be observed.

Animals↗
PubMed1993

Control of torque direction by spinal pathways at the cat ankle joint.

To study the biomechanics of the calcaneal tendon's complex insertion onto the calcaneus, we measured torque-time trajectories exerted by the triceps surae and tibialis anterior muscles in eight unanesthetized decerebrate cats using a multi-axis force-moment sensor placed at the ankle joint. The ankle was constrained to an angle of 110 degrees plantarflexion. Muscles were activated using crossed-extension (XER), flexion (FWR), and caudal cutaneous sural nerve (SNR) reflexes. Torque contributions of other muscles activated by these reflexes were eliminated by denervation or tenotomy. In two animals, miniature pressure transducers were implanted among tendon fibers from the lateral gastrocnemius (LG) muscle that insert straight into the calcaneus or among tendon fibers from the medial gastrocnemius (MG) that cross over and insert on the lateral aspect of calcaneus. Reflexively evoked torques had the following directions: FWR, dorsiflexion and adduction; SNR, plantarflexion and abduction; and XER, plantarflexion and modest abduction or adduction. The proportion of abduction torque to plantarflexion torque was always greater for SNR than XER; this difference was about 50% of the magnitude of abduction torque generated by tetanic stimulation of the peronei. During SNR, pressures were higher in regions of the calcaneal tendon originating from MG than regions originating from LG. Similarly, pressures within the MG portion of the calcaneal tendon were higher during SNR than during XER, although these two reflexes produced matched ankle plantarflexion forces. Selective tenotomies and electromyographic recordings further demonstrated that MG generated most of the torque in response to SNR, while soleus, LG, and MG all generated torques in response to XER.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1978

Regeneration of rabbit calcaneal tendon: a morphological and immunochemical study.

The regenerated tissue which fills the gap between the stumps of sectioned and unsutured rabbit calcaneal tendon was studied by immunofluorescence, light and electron microscopy from 2 days to 30 weeks after surgery. In the early stages, the newly formed tissue consisted of few connective tissue cells of variable shape dispersed in an abundant intercellular matrix. At 7 days after tenotomy most of the cells were spindle shaped and arranged along the major tendon axis. They showed a well developed rough endoplasmic reticulum, a prominent Golgi complex and bundles of thin and thick filaments. Moreover, they appeared intensely stained when treated with anti-actin and anti-myosin sera. The bulk of the intercellular matrix consisted of bundles of collagen fibers, mostly arranged parallel to the cells. In the subsequent stages the regenerating tissue became more compact, acquiring the morphological characteristics of tendon tissue. At 30 weeks after tenotomy, however, it did not show yet the typical texture of the normal adult tendon. The tenocytes were more numerous and less uniformly distributed, and contained a greater amount of ergastoplasm and contractile proteins. The collagen fibers were similar in size to those of the neonatal normal tendon and the elastic fibers appeared often immature.

Actins↗
PubMed1988

Neural site of strabismic amblyopia in cats: X-cell acuities in the LGN.

The acuities of X-cells from the dorsal lateral geniculate nucleus (LGN) were measured in five cats raised with a convergent strabismus, surgically induced by tenotomy. The acuities of cells driven by the strabismic eye were not significantly different from the acuities of cells driven by the non-deviating eye over the range of eccentricities in the visual field studied (from the area centralis to over 20 degrees). The data were also similar to X-cell acuities in the LGN of 3 normal cats. Lowered acuities of LGN X-cells driven by the deviating eye of an esotropic cat in which the strabismus was created by myectomy confirm a previous finding of a retinal locus of amblyopia associated with that preparation. In contrast, the results here implicate the visual cortex as the initial site of the deficit in spatial processing in amblyopia arising from tenotomy strabismus.

Amblyopia↗
PubMed1980

Capillary density of tenotomized skeletal muscles. I. Experimental study in the rat.

Our purpose was to study the capillary density of rat gastrocnemius muscle by microangiography 7-21 days after achillotenotomy or immobilization in a plaster cast. Sixteen animals were tenotomized, 12 immobilized in a plaster cast, and 4 served as controls. The number of capillaries was counted per 1,000 muscle fibres from each sample. No site differences were found in control muscles, where on an average 1,250 capillaries per 1,000 muscle fibers were found. After tenotomy the number of capillaries was decreased 35%, 31%, and 32% on days 7, 14, and 21, respectively. In immobilized muscles the decrease in capillary density occurred slowly, the corresponding decrease being 23%, 33%, and 28% on days 7, 14, and 21, respectively. These results indicate that the capillary density of muscular tissue is greatly decreased following the disuse produced by tenotomy or immobilization.

Achilles Tendon↗
PubMed1983

Bilateral medial rectus muscle recession and lateral rectus muscle resection in the treatment of congenital esotropia.

In a retrospective study of 36 patients with congenital esotropia treated surgically by bilateral medial rectus muscle recession and lateral rectus muscle resection, we found that 22 patients (61%) had not required further surgery and that 14 patients (39%) had required further corrective surgery. Seven of these 14 patients had overcorrections and seven had undercorrections. Patients who required a second operation were significantly younger (mean age, 12 months) than those who did not (mean age, 23 months). The most common second surgical procedure was bilateral tenotomy or disinsertion of the inferior oblique muscle. Bilateral medial rectus muscle recession and lateral rectus muscle resection is useful in severe (50 prism diopters or more) congenital esotropia. The surgical success rate may be improved with bilateral inferior oblique muscle disinsertions or tenotomies in patients with inferior oblique muscle overaction. Accurate preoperative examinations in patients old enough to cooperate may help avoid overcorrection and undercorrection.

Adolescent↗
PubMed1980

Sensitivity of the mature lateral geniculate nucleus to components of monocular paralysis.

Immobilization of the globe by tenotomization of the extrinsic muscles of one eye reduces the encounter rate for X-latency cells in the contralateral dorsal lateral geniculate nucleus (LGN) of adult cats. The reduction in the relative encounter rate for X-latency cells after tenotomy was comparable to that previously observed in the adult cat following concurrent paralysis of the extrinsic and intrinsic muscles of one eye by transection of cranial nerves III, IV, and VI. Paralysis of the intrinsic muscles alone by atropinization, on the other hand, had no detectable effect upon this aspect of LGN physiology. It appears, therefore, that monocular paralysis by cranial nerve section has its effects on LGN X-latency cells through its paralysis of the extrinsic eye muscles. Furthermore, the reduction in the relative encounter rate for X-latency cells produced by tenotomy occurred in spite of early, incomplete return of mobility of the globe. Thus, unilaterally diminished mobility of the globe, in contrast to the complete, sustained immobility characteristic of monocular praralysis, appears sufficient to alter this aspect of LGN physiology in adult cats. The general observation that sensory modifications, in the adult cat, are capable of inducing shifts in the relative recording probabilities for X- and Y-latency cells in the LGN has been repeatedly made. Further, recent, independent observations have provided confirmation for the phenomenon of X/Y ratio shifts in the LGN following adult-onset stimulus modification.

Animals↗
PubMed1977

Vascular changes in flexor tendons after injury and repair: an experimental study.

Two groups of experiments were carried out on the profundus tendons of New Zealand rabbits: 1. Simple closed tenotomies at various levels along the digit. 2. Open tendon division followed by repair with a Bunnell criss-cross suture. At intervals after the operation injection studies were performed to outline the vascular pattern within the tendons. The results indicate that the circulation through the intratendinous vessels is precarious and it may be impaired both by tenotomy and by the presence of sutures. It is suggested that this may be an important factor in the pathogenesis of adhesions. The clinical implications are discussed.

Animals↗