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PubMed1993

DNA histogram typing in a series of 707 tumors of the central and peripheral nervous system.

The diagnostic value of ploidy level was investigated in a series of 707 tumors (from 707 patients) of the central and peripheral nervous system. The series contained 91 nerve sheath tumors (NSTs), 222 meningiomas (MNGs), 37 primitive neuroectodermal tumors (PNETs), 293 glial tumors of the adult (ATTs), and 64 brain metastases (MTTs). The ploidy level of each tumor was obtained by means of its DNA histogram type (DHT), which was computed (digital cell image analysis) on Feulgen-stained nuclei from archival formalin-fixed paraffin-embedded materials. The data reveal that the measurement of the ploidy level showed a diagnostic value in some of these tumor cases. Indeed, the proportion of highly aneuploid cases significantly (p < 0.05-0.01) decreased according to the sequence PNETs (72%)-->MTTs (64%)-->ATTs (40%)-->NSTs (23%)-->MNGs (9%). Nevertheless, this significant diagnostic value in terms of a distinction between benignity and malignancy only appears when all the tumors are taken into consideration. Indeed, at the level of one individual patient, our study shows that, like traumatic neuromas, schwannomas, or classical meningiomas, completely benign tumors can exhibit a high aneuploidy level. In contrast, some tumors from histopathological groups like brain metastases or PNETs, which are known to be clinically aggressive, could be completely diploid.

Astrocytoma↗
PubMed1995

Fatigue brought on by malfunction of the central and peripheral nervous systems.

Increased fatigability necessarily occurs in every patient with muscle weakness, regardless of whether the latter is due to a central or peripheral neurological disorder. The tendency for disuse to increase fatigability, as a secondary phenomenon, must also be considered; disuse affects both motoneuron recruitment and the biochemical and physiological properties of the muscle fibers. In recent studies impaired recruitment has been observed in postpolio patients, while patients with multiple sclerosis or spinal cord injury have shown, in addition, altered neuromuscular function. Findings are also presented in ALS and the chronic fatigue syndrome. In general, the most dramatic increases in fatigability take place in disorders of the peripheral nervous system and almost any cell component can be incriminated. There is a need to study fatigability systematically in neurology and rehabilitation.

Central Nervous System Diseases↗
PubMed1991

Effects of gangliosides on the expression of autoimmune demyelination in the peripheral nervous system.

To test whether gangliosides (GA) might exert neuritogenic effects in vivo, experimental allergic neuritis (EAN) was studied clinically, neuropathologically, and immunologically in Lewis rats immunized with bovine peripheral nerve, P2 myelin protein, P2 myelin protein plus two different doses of GA, P2 with galactocerebroside (GC), and GA alone, each emulsified in adjuvant. All except the GA-treated group developed signs of EAN between days 11 and 14 after the injection. Rats immunized with P2 alone were the most severely affected. Rats given P2 plus GA and those given P2 plus GC displayed a significantly lower clinical score. Histological analysis revealed a comparable degree of inflammation of the peripheral nervous system and demyelination in the spinal nerve roots of bovine peripheral nerve- and P2-immunized rats. The P2 plus GA and P2 plus GC groups revealed similar degrees of pathology in the spinal nerve roots but the latter group stood apart from the rest in that it showed widespread peripheral nervous system changes extending distally into the sciatic nerve. Serological analysis demonstrated that P2 and GC, but not GA, elicited antibody (IgG) responses, but there was no correlation between antibody titer and clinical or histological involvement. The present data fail to support an enhancing role for gangliosides in the expression of EAN and, by extrapolation, in the Guillain-Barré syndrome, for which EAN serves as the laboratory model, and in which suggestions have been made that antibodies to GA may have pathogenetic significance.

Animals↗
PubMed1995

Peripheral nervous system involvement in human and experimental chronic American trypanosomiasis.

An electrophysiological and histological study of the muscle and the peripheral nervous system (PNS) was carried out in chronic human American trypanosomiasis (Chagas' disease) and in an experimental Chagas' disease (Chd) mouse model. Altogether 995 patients with chronic Chd and 261 mice, experimentally infected with RA and CA-I parasite strains, were investigated. Results were compared with matched controls. Techniques employed in humans were: clinical assessment, conventional electromyography (EMG), estimated number of motor units, motor and sensory nerve conduction velocities, repetitive nerve stimulation and muscle and sural nerve biopsies. In mice conventional EMG, sciatic nerve conduction time, sciatic nerve action potential amplitude, in vitro miniature end-plate potentials (MEPPs) and end-plate potentials (EPPs) recordings, muscle, nerve and spinal cord histology and identification of cell phenotypes within the inflammatory infiltrates were the employed procedures. Out of 511 patients submitted to clinical examination, 52 disclosed signs and symptoms of mixed peripheral neuropathy. By employing electrophysiological techniques, it could be shown that about 30% of the investigated patients had one or more of the following features: diminished interference pattern, most of the remainder motor unit potentials being (MUPs) polyphasic; reduced number of functional motor units in the thenar, hypothenar, soleus and/or edb muscles; slow sensory and motor nerve conduction velocities; low sensory action potential amplitude and impairement of neuromuscular transmission. In mice, MUPs duration and amplitude were increased at later stages of the infection, nerve conduction was slow, nerve action potentials were of low amplitude, mepps were of low amplitude and double epps were frequently found. Muscle histology in humans with chronic Chd showed type I and type II grouping, atrophic angular fibers and targetoid muscle fibers. In mice perivascular mononuclear cells infiltrates, small round fibers, muscle fibers necrosis, atrophic angular fibers, type II muscle fibers grouping and grouped muscle fibers atrophy were found. Sural nerve samples showed segmental and paranodal demyelination and axonal loss. The same features were observed in mice nerves, also in this model mononuclear cells infiltrates at the nerve, dorsal root ganglia and meninges surrounding the spinal cord were observed. Muscle and nervous tissues infiltrates were mainly composed of T lymphocytes with predominance of CD8 or CD4 subsets according to the parasites strain employed for infecting the animals. These findings suggest that the skeletal muscle and the PNS may be involved in chronic American trypanosomiasis.

Animals↗
PubMed1991

[A case of paraneoplastic neuropathy with necrotizing arteritis localized in the peripheral nervous system].

A 59-year-old demented Japanese man who was proven to have high titer of serum alpha-fetoprotein (AFP) and carcino-embryonic antigen (CEA) was admitted to our hospital. Neurological examinations revealed moderate dementia with deterioration and loss of memory, and decreased deep tendon reflexes in all extremities. Sensory disturbances were not obvious. There were no significant changes in the usual laboratory findings including CSF, except for elevated serum AFP and CEA. Three months after admission, he died of gastric cancer and its metastases in liver and lymph nodes. Post-mortem examination in the central nervous system (CNS) revealed many senile plaques and neurofibrillary tangles throughout the cerebral cortex and hippocampus. There was marked loss of neurons in the hippocampus. All the neuropathological findings in the CNS were consistent with those in Alzheimer disease. In the peripheral nervous system, necrotizing arteritis was found throughout the length of sciatic nerve. Large myelinated fibers seemed to be preferentially degenerated with proximo-distal gradient. Teased fiber preparation revealed de/remyelination and axonal degeneration more frequently at the distal portion. Immunohistologically, the serum IgG of this patient specifically reacted to the endothelial cells of all vessels in control organs, which strongly suggested the autoimmune mechanism for the necrotizing arteritis in this patient. The pathogenetic role of this antibody for necrotizing arteritis, found selectively in the peripheral nervous system, still remained unclear. However, paraneoplastic neuropathy due to necrotizing arteritis is a distinct entity in addition to common form of paraneoplastic subacute sensory neuropathy.

Alzheimer Disease↗
PubMed2006

Neuroprotection in the peripheral nervous system: rationale for more effective therapies.

Most peripheral neuropathies are length dependent and result in distal axonal degeneration rather than loss of neuronal cell bodies. Available therapies for axonal peripheral neuropathies are designed to control painful symptoms and not to treat the underlying axonal degeneration. Many neuroprotective therapies are being developed, primarily for central nervous system disorders such as stroke or multiple sclerosis. However, strategies with the purpose of promoting survival of injured neurons (ie, preventing cell death) may not be applicable in many peripheral nervous system illnesses when the primary pathologic disorder that leads to symptoms is distal axonal degeneration. Neuronal cell death, if it occurs, is often a late event and may be untreatable in the near future. In contrast, distal axonal degeneration is an early event that may be amenable to treatment. Mechanistic studies that examine the axon-glia interaction and axonal biology are likely to yield novel therapeutic targets for peripheral neuropathies.

Animals↗
PubMed1982

Neural plasticity: Part 3. Responses to lesions in the peripheral nervous system.

This paper describes some of the remarkable recuperative responses that neurons of the peripheral nervous system have to injury of their axons. The initial response is a sealing of the cut ends of the axons, followed by orderly degenerative and phagocytic events in the segments lying distal and proximal to the lesion. The chromatolytic changes occurring in the cell body are adaptive responses involving the morphological, physiological, and biochemical properties of the neuron. The cell loses dendrites and synapses, its electrophysiological properties are altered, and its biochemistry is altered to prepare the neuron for synthesizing proteins needed for formation of growth cones and regeneration of the axon. During this period, the denervated muscle undergoes dramatic atrophic changes that not only modify the electrical nd chemical properties of its membrane but also reduce the diameter and weight of its fibers. This denervation atrophy of muscle is reversible if reinnervation occurs before muscle material has been replaced by connective tissue. Responses to injury of sensory axons depend on the site of the lesion. Cutting a dorsal root causes Wallerian degeneration of the primary afferents' central processes. Collateral sprouts from neighboring uncut root fibers are thought to take over the vacant synapses on the second-order neurons in the dorsal horn. Cutting a sensory axon peripherally eliminates the receptive field of the primary afferent initially, but in time, collaterals from neighboring skin afferents provide the second-order neurons with a new receptive field. Synaptic reclamation and receptive field reorganization are but two dramatic examples of neuronal plasticity that lead to "rewired" neural circuitry.

Atrophy↗
PubMed1985

Synaptic plasticity in the molluscan peripheral nervous system: physiology and role for peptides.

The plasticity of a synapse in the molluscan peripheral nervous system was examined under a variety of experimental, physiological, and pharmacological conditions. These studies employed the isolated salivary glands and attached buccal ganglia of the freshwater snail Helisoma. Action potentials evoked in buccal neuron 4 normally evoke a large excitatory postsynaptic potential (EPSP) which drives an action potential in gland secretory cells. In order to measure modulation of the EPSP, action potential generation in gland cells was prevented by bathing the preparation in low calcium, high magnesium salines. The relationship between the gland EPSP amplitude and specific physiological properties of neuron 4 was analyzed. In common with some central molluscan synapses, the EPSP was found to be strongly influenced by the membrane potential of neuron 4. Specifically, its amplitude was reduced by hyperpolarization of the neuron 4 soma. The relationship between EPSP amplitude and somatic potential of neuron 4 was linear in the range from resting potential (-47 +/- 6mV) to -100 mV. Furthermore, the EPSP amplitude was directly proportional to the action potential half-width of neuron 4. In order to evaluate the possible physiological role of this action potential/EPSP relationship, we examined whether gland EPSPs are modulated during the spike broadening that occurs in both spontaneous burst activity and imposed impulse trains. The preceding action potential/EPSP relationship was maintained under both of these conditions, i.e., EPSP magnitude increased as spikes broadened during bursts or trains. The peptidergic modulation of neuroglandular transmission was also examined. The molluscan peptide SCPB was found to depolarize neuron 4 and an increase in EPSP amplitude was concomitantly observed.(ABSTRACT TRUNCATED AT 250 WORDS)

Action Potentials↗
PubMed1983

Consequences of neural tube and notochord excision on the development of the peripheral nervous system in the chick embryo.

Notochordectomy and neuralectomy were carried out either in one- or in two-step experiments on the chick embryo. The aim of this operation was to study the influence of the axial organs (notochord and neural tube) on the development of the ganglia of the peripheral nervous system. The neural crest cells from which most peripheral ganglion cells arise were labeled through the quail-chick marker system and their fate was followed under various experimental conditions. It appeared that the development of the dorsal root and sympathetic ganglia depends on survival and differentiation of somite-derived structures. In the absence of neural tube and notochord, somitic cells die rapidly, and so do the neural crest cells that are present in the somitic mesenchyme at that time. In contrast, those crest cells which can reach the mesenchymal wall of the aorta, the suprarenal glands, or the gut survive and develop normally into nerve and paraganglion cells. Differentiation of the neural crest- and placode-derived sensory ganglia of the head which develop in the cephalic mesenchyme is not affected by removal of notochord and encephalic vesicles. These results show that the peripheral ganglia are differentially sensitive to the presence of the neural tube and the notochord. Among the various ganglia of the peripheral nervous system, spinal and sympathetic ganglia are the only ones which require the presence of these axial structures. The neural tube allows both the spinal and the sympathetic ganglia to develop in the absence of the notochord. In contrast, if the notochord is left in situ and the neural tube removed, the spinal ganglia fail to differentiate and only sympathetic ganglia can develop.

Animals↗
PubMed1996

The effect of naloxone on spontaneous and evoked dopamine release in the central and peripheral nervous systems.

A number of studies have reported that the opiate antagonist naloxone (NX) inhibits behaviors dependent upon central dopamine (DA) release. However, equally compelling evidence from other studies suggests that NX excites a facilitatory effect. The present review was undertaken to resolve the issue by critically evaluating the effects of NX on DA release; the substrate subserving these behaviors. Included are studies reporting an effect of NX on spontaneous as well as drug altered DA release in various central regions. In the preponderant majority of these studies, NX was found to significantly enhance DA release in the virtually every major DA pathway, irrespective of whether DA release was initially stimulated or inhibited by various agents. It is concluded that NX most probably enhances behaviors induced by DA release, especially when administered in low, specific doses. Studies finding an inhibitory effect of NX on such behaviors may inadvertently produce conditions which mask the stimulatory effects of NX on DA release-dependent behaviors.

Animals↗
PubMed1993

Modulation by GABA of neuroplasticity in the central and peripheral nervous system.

Apart from being a prominent (inhibitory) neurotransmitter that is widely distributed in the central and peripheral nervous system, gamma-aminobutyric acid (GABA) has turned out to exert trophic actions. In this manner GABA may modulate the neuroplastic capacity of neurons and neuron-like cells under various conditions in situ and in vitro. In the superior cervical ganglion (SCG) of adult rat, GABA induces the formation of free postsynaptic-like densities on the dendrites of principal neurons and enables implanted foreign (cholinergic) nerves to establish functional synaptic contacts, even while preexisting connections of the preganglionic axons persist. Apart from postsynaptic effects, GABA inhibits acetylcholine release from preganglionic nerve terminals and changes, at least transiently, the neurochemical markers of cholinergic innervation (acetylcholinesterase and nicotinic receptors). In murine neuroblastoma cells in vitro, GABA induces electron microscopic changes, which are similar in principle to those seen in the SCG. Both neuroplastic effects of GABA, in situ and in vitro, could be mimicked by sodium bromide, a hyperpolarizing agent. In addition, evidence is available that GABA via A- and/or B-receptors may exert direct trophic actions. The regulation of both types of trophic actions (direct, receptor-mediated vs. indirect, bioelectric activity dependent) is discussed.

Acetylcholine↗
PubMed1996

Clinical manifestations of peripheral nervous system involvement in human chronic Chagas disease.

We conducted a clinical and electromyographical study in patients with Chagas' disease in the indeterminate or chronic stages of the illness. Altogether 841 patients were examined. Only 511 were admitted within the protocol; the remainder patients were rejected because they showed other causes able to damage the nervous system. Fifty two (10.17%) out of the 511 patients showed signs and symptoms of peripheral nervous system involvement in the form of sensory impairment and diminished tendon jerks suggesting the presence of neuropathy. Forty five of them were submitted to a conventional electromyographical examination. Fifteen of them showed normal results, while the remainder 30 disclosed a reduced interference pattern, being most of the remaining motor unit potentials fragmented or poliphasic, reduced sensory and motor conduction velocities and diminished amplitude of the sensory action potential. The findings suggest that some chagasic patients in the indeterminate or chronic stages of the disease may develop a clinical mild sensory-motor peripheral neuropathy.

Adolescent↗
PubMed1987

Differential expression of glial- and neuronal-associated antigens in human tumors of the central and peripheral nervous system.

The immunoreactivity of a panel of poly- and monoclonal antibodies raised against different glial and neuronal antigens was investigated in paraffin-embedded specimens of 116 human tumors of the central and peripheral nervous system. We used antibodies against the HNK-1 epitope, which is shared between natural killer cells and the nervous system, glial fibrillary acidic protein (GFAP), vimentin, neurofilaments, S-100 protein, neuron-specific enolase (NSE) and myelin basic protein (MBP). HNK-1 immunoreactivity was detectable in nearly all neuroectodermal tumors. Especially in those derived from the neuroepithelium, which include the various types of gliomas, we observed a strong staining with this antibody. The only exceptions were the choroid plexus papillomas and individual ependymomas. In tumors derived from the neural crest HNK-1 reactivity was more variable and less intense. In other tumors of the nervous system HNK-1 was not detectable, except for two out of four malignant lymphomas. In addition to its reactivity with human lymphocytes HNK-1, therefore, seems to be a useful 'marker' for neurogenic tumors in general. GFAP expression was prominent in all astrocytomas and the astrocytic cells within mixed gliomas and gangliogliomas. Immunoreactivity was more variable in glioblastomas and ependymomas, while only isolated GFAP-positive cells were present in oligodendrogliomas, medulloblastomas, one plexus papilloma, and some neurinomas. Vimentin immunoreactivity was found in tumor cells of nearly all tumors of the central nervous system with the exception of oligodendrogliomas, most plexus papillomas, neuronal tumors and most medulloblastomas.

Antibodies, Monoclonal↗
PubMed1986

Distribution of fibroblast growth factor in the central and peripheral nervous systems of various mammals.

Fibroblast growth factor (FGF) is a potent, mesodermal cell mitogen which has been identified throughout the central nervous system of various mammals and shown to display no regional concentration differences within the brain. An FGF-like mitogen of similar specific activity is also identified in the peripheral nervous system. Although not myelin-derived, these factors may arise from some component, of neuronal or glial origin, common to the central and peripheral nervous systems.

Animals↗