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At least 523 records · Page 29Linked to original sources
PubMed1997

Expression of a new M(r) 70-kDa dystrophin-related protein in the axon of peripheral nerves from Torpedo marmorata.

By comparison with localizations of dystrophin family products in rabbit peripheral nerves, we investigated the potential existence and distribution of similar products in peripheral nerves from Torpedo marmorata. In immunofluorescence studies, a specific set of monoclonal antibodies directed against dystrophin family proteins clearly stained a thin rim surrounding each Schwann cell-axon unit both in T. marmorata and rabbit peripheral nerves. In contrast when using the dystrophin/utrophin monoclonal H'3E7 antibody, we found a clear difference between rabbit and T. marmorata peripheral nerves according to fluorescent labeling detected within Torpedo nerve axons. Further differences were noted following western blot analyses of T. marmorata peripheral nerve extracts, highlighting the presence of a new and specific M(r) 70-kDa protein band belonging to the dystrophin family, which is localized within axons in addition to: (1) an M(r)400-kDa protein band detected with dystrophin/utrophin antibodies; and (2) an M(r) 116-kDa doublet protein band corresponding to Dp116 and Up116 isoforms. All of these products, detected according to the specificities of the monoclonal antibodies used, are discussed in terms of their potential identities as short and long dystrophin or utrophin mammalian products.

Animals↗
PubMed2000

[Ultrastructural study on the peripheral nerve and skeletal muscle of patients with spastic cerebral palsy].

OBJECTIVE: To explore pathological features of the peripheral nerve and skeletal muscle of patients with spastic cerebral palsy. METHODS: The peripheral nerve and skeletal muscle of 25 patients with spastic cerebral palsy were observed by gross examination during operation, and under microscope and electron microscope. RESULTS: Gross examination showed that peripheral nerve and skeletal muscle was normal during operation. Microscope showed that some skeletal muscle fibers degenerated, and the connective tissue proliferated. electronmicroscopically the damage of demyelination was extensive on the peripheral nerve; the pathological changes of Schwann's cell were sooner and more severe than axons; the pathological changes of myelinated nerve fiber were more obvious than the nonmyelinated nerve fiber; the lymphocyte were found around the microvasculature within the perineurium; the mitochondrion of skeletal muscle fiber increased in number, the sarcoplasmic reticulum and transverse tubule decreased and developed badly, the degenerative muscle fiber showed cell edema or the pathological changes of myofibril. All the peripheral nerve and skeletal muscle fiber affected had no repair and regeneration. CONCLUSIONS: The demyelination of the peripheral nerve of patients with spastic cerebral palsy is primary, and the skeletal muscle of patients with spastic cerebral palsy is secondary pathological change. The activity of nerve and muscle regeneration is bad.

Adolescent↗
PubMed2002

Histological and electrophysiological analysis of the peripheral nerve allografts using an immunosuppressive agent.

In peripheral nerve allografts, use of an immunosuppressive agent is one of the ways of reducing nerve rejection. FK506 is a newly discovered substance, extracted from Streptomyces tsukubaensis, and has strong immunosuppressive effects. In the present study, immunosuppressive effects of FK 506 were examined using allografts of rat sciatic nerves. Good nerve regeneration was demonstrated through 12 weeks in this model. The immunosuppressed group gained weight over the course of the experiment. Another study was performed to observe the histological changes caused by ceasing the administration of FK506. Administration of FK506 was terminated 12 weeks after grafting. At 8 weeks after cessation, cellular infiltration and large unmyelinated axons were observed in the extended subperineurial space of grafts. At 12 weeks, histological characteristics of rejection were not observed. In the electrophysiological study, the temporal dispersions were recorded at 4 and 8 weeks. However, the normal electrophysiological waves were recorded at 12 weeks after cessation. It was concluded that FK506 is effective for preventing rejection of nerve allografts without any serious side effects on rats, and findings of total rejection of grafts were not recognized after ceasing the administration of FK 506. In peripheral nerve allografts, short-term administration of an immunosuppressive agent is sufficient to lead to good nerve regeneration.

Action Potentials↗
PubMedDate not supplied

The cellular and molecular basis of peripheral nerve regeneration.

Functional recovery from peripheral nerve injury and repair depends on a multitude of factors, both intrinsic and extrinsic to neurons. Neuronal survival after axotomy is a prerequisite for regeneration and is facilitated by an array of trophic factors from multiple sources, including neurotrophins, neuropoietic cytokines, insulin-like growth factors (IGFs), and glial-cell-line-derived neurotrophic factors (GDNFs). Axotomized neurons must switch from a transmitting mode to a growth mode and express growth-associated proteins, such as GAP-43, tubulin, and actin, as well as an array of novel neuropeptides and cytokines, all of which have the potential to promote axonal regeneration. Axonal sprouts must reach the distal nerve stump at a time when its growth support is optimal. Schwann cells in the distal stump undergo proliferation and phenotypical changes to prepare the local environment to be favorable for axonal regeneration. Schwann cells play an indispensable role in promoting regeneration by increasing their synthesis of surface cell adhesion molecules (CAMs), such as N-CAM, Ng-CAM/L1, N-cadherin, and L2/HNK-1, by elaborating basement membrane that contains many extracellular matrix proteins, such as laminin, fibronectin, and tenascin, and by producing many neurotrophic factors and their receptors. However, the growth support provided by the distal nerve stump and the capacity of the axotomized neurons to regenerate axons may not be sustained indefinitely. Axonal regenerations may be facilitated by new strategies that enhance the growth potential of neurons and optimize the growth support of the distal nerve stump in combination with prompt nerve repair.

Animals↗
PubMed1996

Transverse-field activation mechanism in magnetic stimulation of peripheral nerves.

The activating function of peripheral nerves in magnetic stimulation is thought to be the gradient of the induced electric field component parallel to the nerve. This implies that there are several orientations of the coil that should not excite nerves. We show that these orientations, however, often yield high-amplitude and even supramaximal muscle response, indicating that the model of the activating function has to be modified. We propose that the electric field component perpendicular to the nerve is responsible for these unexpected muscle responses. Our conclusion is based on practical experiments with different coils and on computer simulations of the induced electric field and its gradient.

Electric Stimulation↗
PubMed1999

Intraneural angiosarcoma and angiosarcoma arising in benign and malignant peripheral nerve sheath tumours: clinicopathological and immunohistochemical analysis of four cases.

AIMS: Angiosarcomatous differentiation represents the least common form of heterologous differentiation in malignant peripheral nerve sheath tumours (MPNST), and is seen most frequently in patients with neurofibromatosis type 1. More rarely, it has been reported in patients without stigmata of neurofibromatosis, or in benign nerve sheath tumours and peripheral nerves. This study was undertaken to confirm this rare association. METHODS AND RESULTS: Four cases of angiosarcoma arising in a peripheral nerve, in a long-standing schwannoma and in two MPNST are described. Immunohistochemical studies were performed on paraffin sections with the alkaline phosphatase-antialkaline phosphatase method. An intraneural high-grade epithelioid angiosarcoma arose in the left posterior tibial nerve of a 78-year-old man, a well to moderately differentiated angiosarcoma was seen in an ancient schwannoma of the lateral neck in a 73-year-old women, and an angiosarcoma of varying grades of differentiation developed in a recurrent MPNST in the thigh of 38-year-old man. In addition a high-grade MPNST in the axillary region of a 30-year-old man showed foci of heterologous high-grade angiosarcomatous differentiation. The neural and endothelial lines of differentiation were confirmed in each case by positive immunohistochemical staining for neural and endothelial markers, respectively. In all cases tested, the neural differentiated cells stained immunohistochemically positive for antibodies against vascular endothelial growth factor. CONCLUSIONS: This study confirms the rare association of angiosarcoma arising in peripheral nerves, as well as in benign and malignant peripheral nerve sheath tumours.

Adult↗
PubMed2004

[Advances in peripheral nerve allograft].

OBJECTIVE: To investigate the research advances of the peripheral nerve allograft. METHODS: The recent articles on peripheral nerve allograft were reviewed extensively. The treatments of allograft and host were analyzed. RESULTS: The immunogenicity of allograft was relieved by the physical, chemical or biological treatments; the immunosuppressive therapy makes the rejection relieved and the regeneration of axon accelerated. CONCLUSION: The effect of peripheral nerve allograft is inferior to autograft. If the immunologic tolerance are induced successfully, the problem shall be solved.

Animals↗
PubMed1976

Peripheral nerve stimulation in the treatment of intractable pain.

Peripheral nerve stimulating devices were implanted for pain control in 33 patients with a variety of disabling chronic pain conditions, which had persisted despite usual medical and surgical therapy. The implants were placed on major nerves innervating the area of the patient's pain. Records were obtained of each patient's stated relief from pain produced by nerve stimulation, along with assessments of narcotic withdrawal, ability to return to work, sleep pattern, and relief from depression. Based on these five criteria 17 patients were judged to be treatment failures, while eight patients had excellent results, and seven had intermediate results. Twelve of the failures were in patients with either low back pain with sciatica, or pain from metastatic disease. The most dramatic successes occurred in patients with peripheral nerve trauma. The incidence of complications has been low, and two patients have used the stimulator for 5 years without adverse effects. Techniques of peripheral stimulator implantation, possible mechanisms of action, and conclusions regarding peripheral nerve stimulation in the treatment of chronic pain are discussed.

Adolescent↗
PubMed1982

Peripheral nerve injuries. Nerve sutures and nerve grafting.

In the repair of transected peripheral nerves it is attempted to achieve an optimal coaptation of the fascicular tissue. A certain amount of fibroblast activity is essential for nerve regeneration but the fibroblast activity should not be overwhelming. At present fibroblast activity can be reduced only -by resection of the epineural tissue in nerve segments, in which it represents a high percentage of the cross-section (polyfascicular nerve structure with group arrangement), -by reducing the surgical trauma to a minimum, -by reducing the application of foreign material to a minimum, -by avoiding tension at the suture site, -by performing a proper resection, and -by adjusting the type of coaptation to the structure prevailing in the two nerve stumps. In clean cuts without major complications primary nerve repair is recommended. The patients have to be followed and, if within six months no signs of recovery occur, re-exploration is indicated. Complicated cases with nerve defects should be treated by early secondary repair. If during secondary repair an end-to-end coaptation can not be achieved easily, the application of nerve grafts is the treatment of choice.

Axons↗
PubMed1976

Purification and partial characterization of two glycoproteins in bovine peripheral nerve myelin membrane.

Two major glycoproteins of bovine peripheral nerve myelin were isolated from the acid-insoluble residue of the myelin by a procedure involving delipidation with chloroform/methanol (2:1, v/v) and chromatography on Sephadex G-200 column with a buffer containing sodium dodecyl sulfate. The separation patterns of the proteins on the gel were affected considerably by the dodecyl sulfate concentration in the elution buffer. At above 2% dodecyl sulfate concentration in the elution buffer, the glycoproteins, could be separated clearly on the gel and were purified. The purified proteins, the BR protein (mol. wt. 28 000) and the PAS-II protein (mol. wt. 13 000), were homogeneous on dodecyl sulfate-polyacrylamide gel electrophoresis. The NH2- terminal amino acids of the BR and the PAS-II proteins were isoleucine and methionine, respectively. The BR protein contained glucosamine, mannose, galactose, fucose and sialic acids and the PAS-II protein contained glucosamine, mannose, galactose, fucose and glucose. Neither the BR protein nor the PAS-II were a glycosylated derivative of a basic protein of bovine peripheral nerve myelin, a deduction based on the results of amino acid analysis. The two major glycoproteins were observed commonly in the peripheral nerve myelin of cows, pigs, rabbits and guinea pigs, using dodecyl sulfate-polyacrylamide gel electrophoresis.

Amino Acid Sequence↗
PubMed2002

[Role of thyroid hormone in peripheral nerve regeneration].

OBJECTIVE: To review the role of thyroid hormone in the peripheral nerve regeneration. METHODS: The recent literatures of experimental study and clinical application on the role of thyroid hormone in nerve regeneration were reviewed. The researches on expression, isoform and changes of thyroid hormones in rat sciatic nerve in normal or injury were summarized. The effect of thyroid hormone on local rat sciatic nerve was studied, too. RESULTS: Nuclear thyroid hormone receptors expressed in numerous nuclei of sciatic nerve during a limited period of development extending from the third week of embryonic life to the end of the second postnatal week and after injury of adult sciatic nerve. A single and local administration of thyroid hormone at the level of the transected sciatic nerve produced a lasting effect on peripheral nerve regeneration. CONCLUSION: The beneficial effects of thyroid hormones upon injured peripheral nerve may have considerable therapeutic potential.

Animals↗
PubMed1998

Peripheral nerve grafts exert trophic and tropic effects on anterior thalamic neurons.

Peripheral nerve grafting into the central nervous system (CNS) has been used to study the regenerative capabilities of central neurons given access to a peripheral nervous system (PNS) environment. It is well documented that many CNS neurons regenerate axons along peripheral nerve grafts placed in close proximity to their cell bodies and that these grafts can ameliorate axotomy-induced retrograde degeneration. In the present study, we placed peripheral nerve grafts in proximity to axotomized neurons of the anterior thalamus. Standard histological and retrograde tracing techniques were used to examine these preparations 2 months after grafting. Three effects of these grafts were observed: amelioration of retrograde degeneration of axotomized anterior thalamic neurons, hypertrophy of many thalamic neurons in the local environment of the graft, and ingrowth of axons of axotomized anterior thalamic neurons as well as nonaxotomized neurons from surrounding nuclei. We conclude from these studies that peripheral nerve grafts not only provide a matrix for axonal outgrowth but also exert marked trophic and tropic effects on axotomized anterior thalamic neurons.

Animals↗
PubMed1993

Vein graft conduits versus conventional suturing in peripheral nerve reconstructions.

Positive results of tubulization in peripheral nerve reconstruction have been established in animals by many investigators. Clinically, tubulization by means of a venous tubulus is accepted as a reliable technique, but histological results are not known and functional analysis is limited. The aim of this investigation was to study the histological effect of venous tubuli in peripheral nerve reconstruction. In 20 rabbits the saphenous nerves were transected and anastomosed. In ten rabbits (series 1) a venous tubulus was placed around the nerve suture. In another ten rabbits (series 2) a venous tubulus was sutured over a 3 mm nerve gap. Conventional suturing was done in ten contralateral saphenous nerves (series 3, controls). Epineurial stitching was performed. The healing was studied after 3 months and after that histological analysis was performed by means of monoclonal antibody staining. The results of our experiments show that covering a nerve anastomosis with a venous tubulus did not enhance healing in comparison to the conventional end-to-end anastomosis, but in contrast evoked extensive fibrous tissue, thereby hampering regeneration of axons.

Animals↗
PubMed2006

Large-scale molecular comparison of human schwann cells to malignant peripheral nerve sheath tumor cell lines and tissues.

Malignant peripheral nerve sheath tumors (MPNST) are highly invasive soft tissue sarcomas that arise within the peripheral nerve and frequently metastasize. To identify molecular events contributing to malignant transformation in peripheral nerve, we compared eight cell lines derived from MPNSTs and seven normal human Schwann cell samples. We found that MPNST lines are heterogeneous in their in vitro growth rates and exhibit diverse alterations in expression of pRb, p53, p14(Arf), and p16(INK4a) proteins. All MPNST cell lines express the epidermal growth factor receptor and lack S100beta protein. Global gene expression profiling using Affymetrix oligonucleotide microarrays identified a 159-gene molecular signature distinguishing MPNST cell lines from normal Schwann cells, which was validated in Affymetrix microarray data generated from 45 primary MPNSTs. Expression of Schwann cell differentiation markers (SOX10, CNP, PMP22, and NGFR) was down-regulated in MPNSTs whereas neural crest stem cell markers, SOX9 and TWIST1, were overexpressed in MPNSTs. Previous studies have implicated TWIST1 in apoptosis inhibition, resistance to chemotherapy, and metastasis. Reducing TWIST1 expression in MPNST cells using small interfering RNA did not affect apoptosis or chemoresistance but inhibited cell chemotaxis. Our results highlight the use of gene expression profiling in identifying genes and molecular pathways that are potential biomarkers and/or therapeutic targets for treatment of MPNST and support the use of the MPNST cell lines as a primary analytic tool.

Apoptosis↗
PubMed2003

Repair of peripheral nerve transections with fibrin sealant containing neurotrophic factors.

Peripheral nerve injury is often followed by incomplete recovery of function and sometimes associated with neuropathic pain. There is, therefore, need for therapies which improve the speed of recovery and the final functional outcome after peripheral nerve injuries. In addition, neuropathic pain is not easily dealt with clinically and should preferably be eliminated. Neurotrophic factors have well-documented abilities to support neuron survival and stimulate neurite outgrowth, making them excellent candidates for use in repairing injured nerves. We investigated the possible beneficial effects of repairing the transected rat sciatic nerve by local application of a fibrin sealant containing nerve growth factor (NGF), glial cell line-derived neurotrophic factor (GDNF), or acidic fibroblast growth factor (aFGF). Fibrin sealant was used in conjunction with sutures. Evaluation of motor and sensory function, autotomy, and histological parameters was carried out from 1 to 12 weeks after injury. We demonstrate that NGF cotreatment decreased the occurance of autotomy, suggesting a reduction of neuropathic pain, and improved the performance in motor and sensory tests. In addition, the number of regenerating motoneurons was significantly increased after NGF administration. GDNF increased the speed of sensory recovery, but also markedly increased autotomy, indicating an increased degree of neuropathic pain. aFGF did not alter the outcome of the motor or sensory tests. Fibrin sealant could easily be used in conjunction with sutures to deliver neurotrophic substances locally to the damaged nerve and to enhance recovery of nerve function.

Animals↗