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Identification of the Schwann cell as a peripheral nervous system cell possessing a differentiation antigen expressed by a human lung tumor.

Recent studies of the plasma membrane antigens of a human lung tumor (oat cell carcinoma) indicated that the tumor expressed at least two normal differentiation antigens undetectable in normal respiratory epithelium. One antigen was characteristic of certain endodermally derived epithelial cells of the digestive system; the other antigen was characteristic of certain neural crest-derived cells in the peripheral nervous system. The present studies were undertaken to identify the reactive cell type in the peripheral nervous system. Since similar cells in the rat peripheral nervous system expressed a cross-reactive form of this antigen, and since pure cultures of different rat nerve cell type were available, the following approach was possible. Cultures of pure neurons, pure Schwann cells, pure fibroblasts, neurons and Schwann cells, and neurons, Schwann cells, and fibroblasts were assayed for this antigen with rabbit anti-oat cell carcinoma plasma membrane antiserum absorbed with normal lung and liver. The indirect immunofluorescence method on both whole, viable cell and fixed cell substrates was used. Only Schwann cells expressed the antigen; Schwann cells in the presence of neurons expressed the antigen much more strongly than did pure Schwann cells. It was concluded that the oat cell carcinoma of the lung expressed a differentiation antigen present on Schwann cells.

Animals↗

Primitive neuroectodermal tumors, embryonal tumors, and other small cell and poorly differentiated malignant neoplasms of the central and peripheral nervous systems.

Many different types of small cell, embryonal, and poorly differentiated neoplasms originate within the central and peripheral nervous systems. Because appropriate treatment is based on a correct diagnosis, the surgical pathologist must be familiar both with basic characteristics of each of the numerous entities as well as the spectrum of morphologic features that each may display. The nosology and nomenclature of these tumors have a rich and varied history. One basic distinction is between primitive neuroectodermal tumors of the central nervous system (cPNETs) and primitive neuroectodermal tumors of the peripheral nervous system (pPNETs), which are clinicopathologically and genetically distinct. Among the cPNETs are medulloblastoma, pineoblastoma, cerebral neuroblastoma, ependymoblastoma, medulloepithelioma, primary rhabdomyosarcoma, and atypical teratoid/rhabdoid tumor, whereas the pPNETs comprise the more differentiated end of a spectrum of neoplasms that include skeletal and extraskeletal Ewing's sarcoma.

Central Nervous System Neoplasms↗

Advantages of mouse models to study early steps of peripheral nervous system development.

The molecular mechanisms involved in the formation of mammalian peripheral nervous system remain largely unknown. Here we describe the new possibilities offered by mouse mutant analysis, new mouse in vitro models and the recent development of molecular genetic techniques which may permit analysis of the peripheral nervous system development at a level that was heretofore restricted to lower vertebrates.

Animals↗

Murine central and peripheral nervous system transcriptomes: comparative gene expression.

The central and peripheral nervous systems exhibit significant embryological, morphological, and functional differences. Moreover, the pathology of most acquired and hereditary neurological diseases preferentially targets specific components of the nervous system. In order to test the hypothesis that central and peripheral neural transcriptomes show fundamental quantitative differences, Affymetrix GeneChip expression arrays were used to compare murine lumbar spinal cord (SC) and dorsal root ganglion (DRG) gene expression. As the crucial component of a novel technique to preserve RNA integrity, mice were perfusion-fixed with RNAlater before the SC and DRG were harvested. As per Affymetrix terminology, a total of 111 transcripts were present (P) on all DRG arrays, absent (A) on all SC arrays, and demonstrated at least 10-fold greater expression in DRG than in SC. Conversely, a total of 112 transcripts were present on all SC arrays, absent on all DRG arrays, and showed at least 10-fold greater expression in SC than in DRG. For a subset of transcripts, quantitative real-time RT-PCR was used to corroborate and validate microarray results. Among those genes enriched in DRG, many belonged to a few distinct functional classes: G-protein coupled receptor-protein signaling pathways, potassium transport, sodium transport, sensory perception, and cell-surface receptor-linked signal transduction. In contrast, genes associated with synaptic transmission, organic acid transport, neurotransmitter transport, and circulation were enriched in SC. Notably, the majority of genes causally associated with hereditary neuropathies were highly enriched in DRG. These differential neural gene expression profiles provide a robust framework for future molecular and genetic studies of neuropathy and SC diseases.

Animals↗

How does Mycobacterium leprae target the peripheral nervous system?

Mycobacterium leprae has the capacity to invade the peripheral nervous system and cause neuropathy. The molecular mechanisms responsible have remained unknown until recently. Identification of the endoneurial laminin-2 isoform and its receptor alpha-dystroglycan as neural targets of M. leprae has not only opened up a new area of scientific inquiry into the pathogenesis of neurological damage in leprosy, but has also revealed unexpected biological properties of these important host molecules.

Cytoskeletal Proteins↗

Pathogenesis of mouse scrapie: evidence for spread of infection from central to peripheral nervous system.

The onset of replication has been studied in spinal cord, dorsal root ganglia and spinal nerves of CW mice infected intraperitoneally with the 139A strain of scrapie. The patterns obtained suggest a centrifugal spread of infection from central to peripheral nervous systems. Infectivity titres in the peripheral nervous system reached a plateau long before the end of the incubation period, and the maximum titres were much lower than in the central nervous system. This suggests that there is a restriction of replication in the peripheral nervous system similar to that already known in extraneural tissues.

Animals↗

[Involvement of the peripheral nervous system in HIV infection: electromyographic study and nerve conduction velocity].

Disorders of the peripheral nervous system occur at all stages of HIV1 infection. Acute and subacute inflammatory demyelinating polyneuropathies are mainly observed in otherwise asymptomatic HIV+ patients and in patients with ARC (AIDS-related complex): clinical and electrophysiological features are similar to those observed in Guillain-Barré syndrome (GBS) and chronic inflammatory demyelinating polyneuropathy (CIDP), but CSF examination usually shows pleocytosis, and an infiltration of the endoneurium and/or the epineurium is commonly seen in nerve biopsies. Mononeuropathy multiplex is a rare complication occurring in ARC-patients: electrophysiological studies are consistent with an axonopathy and nerve biopsies may show vasculitis. Distal predominantly sensory polyneuropathies are the most frequent peripheral neuropathies in HIV1 infection and are usually reported in patients with AIDS and severe immunosuppression: electrophysiological features are of an axonopathy with signs of acute denervation. Meningoradiculitis is observed at the late stages of the disease and is mainly due to a cytomegalovirus infection. On the other hand, systematic electrophysiological studies in HIV+ cases reveal a high percentage of abnormalities concerning sensory and less frequently motor nerve conduction velocities. The severity of this asymptomatic involvement of the peripheral nervous system seems to be related to the degree of the immunodeficiency. The mechanism of these peripheral neuropathies remains hypothetical in most cases.

Electromyography↗

Magnetic resonance imaging of the peripheral nervous system.

An accurate diagnosis is the essential first step toward a successful treatment plan in patients who present with pain and suspected nerve entrapment. Pain and dysfunction are often related to an acute traumatic event or a classic presentation that leads to a straightforward clinical diagnosis. The diagnostic approach to abnormalities of the peripheral nervous system always begins with a thorough history and physical examination. Imaging may play an important role in confirming the initial clinical [figure: see text] diagnosis so that a rational plan of treatment may be selected. Diagnostic imaging is especially important when there is significant uncertainty regarding the cause of pain and the outcome may be improved by timely implementation of various treatment options. Diagnostic accuracy is important when various conditions in the differential diagnosis would be treated differently from the beginning. Indeed, certain conditions that result in pain and dysfunction related to peripheral nerve entrapment are best treated with initial rest, protection, and rehabilitation whereas other conditions are best treated with prompt surgery. Promptly arriving at an accurate diagnosis is an essential step in designing a rational course of therapy, in achieving a good outcome, and in treating medical conditions in a timely fashion. Indeed, because pain is mediated through peripheral nerves, establishing an accurate diagnosis is especially important in disorders of the peripheral nervous system in which there may be considerable pain and suffering with an incorrect or delayed diagnosis. Moreover, an early diagnosis is desirable [figure: see text] to preserve motor power and sensory function in cases of clinically occult nerve entrapment. Although entrapment syndromes are well described and widely documented in the literature, they may be easily missed in clinical practice in certain instances. Although MR imaging is useful to confirm and characterize a known or suspected case of peripheral nerve entrapment, there may be evidence of peripheral nerve pathology that is first detected with MR imaging. Clinically unsuspected nerve entrapment may occur in patients with occult dorsal ganglion cysts in the wrist that may entrap the posterior interosseous nerve and produce pain without other symptoms. In addition, the authors routinely see patients with paralabral cysts secondary to tears of the superior labrum in the shoulder resulting in entrapment of the suprascapular nerve. This diagnosis is usually not suspected clinically until there is relatively advanced weakness and muscular atrophy in addition to shoulder pain. MR imaging remains an evolving technique with ongoing improvements in technology and developing clinical experience, resulting in greater diagnostic capacity. In this article current technique and strategies for image analysis and the authors' specific clinical experience with MR imaging of peripheral nerve disorders are reviewed. The exact role of MR imaging in the evaluation of these disorders will be further defined with additional experimental work and published clinical experience.

Humans↗

Evolutionarily conserved mechanisms regulating neural development: lessons from the development of Drosophila peripheral nervous systems.

Functions of genes regulating the development of Drosophila peripheral nervous systems are summarized herein. These genes can be classified into 6 groups: <1> prepattern genes, <2> proneural genes, <3> neurogenic genes, <4> neuronal precursor genes, <5> neuronal precursor type selector genes, and <6> cell-division and lineage genes. The mechanisms described herein provide excellent paradigms in the regulation of the development of other tissues in Drosophila, as well as in other organisms, including vertebrates. The roles of two different inhibitory mechanisms, i.e. Notch-signaling and Argos, in the development of Drosophila neural precursor cells are also discussed.

Animals↗

Central and peripheral nervous system functions are independently disturbed in HIV-1 infected patients.

We examined the peripheral nervous system (PNS) (nerve conduction velocity (NCV)) and the central nervous system (CNS) (basal ganglia-mediated psychomotor speed) in 93 males seropositive for human immunodeficiency virus type 1 (HIV-1) with no prior history of opportunistic brain disease, antiretroviral treatment or intravenous drug use. Patients with different degrees of slowing of peroneal and sural NCV showed no significant differences in psychomotor speed as assessed by tremor peak frequency, most rapid alternating movements, reaction times and contraction times. There was no significant correlation between psychomotor measures and NCV. Psychomotor slowing test findings were independent from peripheral nervous system damage indicating uncorrelated disturbances of CNS and PNS function in HIV-1 infection. Differences in HIV-1 viral quasispecies or host responses may determine the predominance of CNS or PNS injury.

AIDS Dementia Complex↗

Acute carpal tunnel syndrome in a diver: evidence of peripheral nervous system involvement in decompression illness.

Conclusive evidence for involvement of the peripheral nervous system in decompression illness is lacking. We report a case of decompression illness associated with shoulder pain and the clinical features of median nerve injury at the wrist. Initial recompression and hyperbaric oxygen treatment produced prompt relief of all symptoms and signs, but carpal tunnel syndrome subsequently recurred. Nerve conduction studies confirmed median nerve conduction delay at the wrist. Repeat measurements after treatment with hyperbaric oxygen showed electrophysiologic improvement that was consistent with improvement in symptoms. We believe this is the first objectively substantiated case of injury to the peripheral nervous system caused by decompression illness.

Acute Disease↗

Involvement of the hypothalamic--pituitary--adrenal/gonadal axis and the peripheral nervous system in rheumatoid arthritis: viewpoint based on a systemic pathogenetic role.

From the compendium presented above, the following statements become evident: 1) Inappropriately low secretion of cortisol in relation to inflammation is a typical feature of the inflammatory disease in patients with RA. 2) The secretion of adrenal androgens is significantly reduced, which is a problem in postmenopausal women and elderly men due to a lack of downstream sex hormones. 3) Serum levels of testosterone are markedly reduced in RA. 4) Sympathetic nerve fibers are markedly reduced in the synovial tissue of patients with RA, whereas proinflammatory sensory fibers (substance P) are present. 5) Substance P serves to continuously sense painful stimuli in the periphery, and the nociceptive input from the inflamed joint shows a large amplification in the spinal cord. This leads to continuous pain with stabilization of the afferent sensory input and continuous release of proinflammatory substance P into the lumen of the joint. From these facts it is obvious that alterations of the systemic antiinflammatory feedback systems contribute significantly to the pathogenesis of RA. Disease therapy directed at these alterations must provide a mechanism to replace the adrenal glands (glucocorticoids), the gonadal glands (androgens), and the sympathetic nervous system (adenosine increase by low-dose MTX, sulfasalazine, and salicylates) in order to integrate their immunosuppressive effects at the local site of synovial inflammation. Although local processes of the adaptive immune system are important in pathogenesis in the acute phase of RA, these mechanisms may be less important during the chronic phase of the disease in the absence of a specific trigger. We believe that a defect of systemic antiinflammatory feedback systems is an important factor in the perpetuation of RA. This review reinforces the belief that combined therapeutic approaches on a neuroendocrine immune basis are of crucial importance in a pathogenetically oriented therapy of RA.

Arthritis, Rheumatoid↗

Lyme neuroborreliosis. Peripheral nervous system manifestations.

An ever increasing number of apparently unrelated peripheral nervous system (PNS) disorders has been associated with Lyme borreliosis. To ascertain their relative frequency and significance, we studied prospectively 74 consecutive patients with late Lyme disease, with and without PNS symptoms: 53% had intermittent limb paraesthesiae, 25% the carpal tunnel syndrome, 8% painful radiculopathy, and 3% Bell's palsy; 39% had disseminated neurophysiological abnormalities. To assess the interrelationships among these syndromes, we reviewed the neurophysiological findings in all 163 such patients that we have studied to date. Reversible abnormalities of distal conduction were the most common finding. Demyelinating neuropathy was extremely rare. The pattern of abnormality was similar in all patient groups, regardless of whether the symptoms suggested radiculopathy, Bell's palsy, or neuropathy. We conclude that (1) reversible PNS abnormalities occur in one-third of our patients with late Lyme borreliosis, and (2) the pattern of electrophysiological abnormalities is the same in all and is indicative of widespread axonal damage, suggesting that these different presentations reflect varying manifestations of the same pathological process.

Adolescent↗

Central and peripheral nervous system effects of hand-arm vibrating tool operation. A study of brainstem auditory-evoked potential and peripheral nerve conduction.

To examine the effects of hand-arm vibrating tool operation on the central and peripheral nervous system, the brainstem auditory-evoked potential (BAEP), median nerve conduction velocity and hearing level were measured in twelve chain saw operators (6 operators had a history of white finger attack) and in eight brush saw operators (none had a history of the attack). Control subjects, matched to each chain saw and brush saw operator by sex and age, were selected randomly from healthy adults without otitis, deafness and tinnitus. The I-V interpeak latency (conduction from cochlear nerve to brainstem) and V peak latency of BAEP were significantly prolonged in chain saw operators; the I-V interpeak latency was significantly correlated with working years in brush saw operators. The median nerve conduction velocity was significantly slowed in both chain saw and brush saw operators. Moderate hearing loss was observed in the two groups. It is suggested that vibrating tool operation, i.e. the combined stressors of local vibration, noise, climate and heavy work, affected not only the peripheral nervous system but also the brainstem portion of the auditory pathway; the brainstem effect, if any, is less advanced than the peripheral nervous system effect of local vibration.

Adult↗

Damage of cutaneous peripheral nervous system evolves differently according to the disease phase and subset of systemic sclerosis.

OBJECTIVE: Evidence shows that peripheral nervous system (PNS) is involved in systemic sclerosis (SSc), but few morphological studies have assessed the ultrastructural pathological modifications. The aim was to study ultrastructural modifications of skin PNS fibres in SSc according to subsets [limited SSc (lSSc) and diffuse SSc (dSSc)] and phases (early and advanced) of the disease. METHODS: Skin biopsies were taken from the forearms of 23 SSc patients (11 lSSc and 12 dSSc) and 10 controls. Each biopsy was processed for transmission electron microscopy (TEM). RESULTS: At TEM, observation in skin from early lSSc, signs of inflammation were evident, while PNS fibres were not damaged. The microvascular wall showed hypertrophic endothelial cells bulging into the lumen. In advanced lSSc, fibrosis prevailed on inflammation and slight ultrastructural alterations of PNS fibres were evident in the papillary derma. In early dSSc, ultrastructural alterations of PNS fibres, similar to those observed in the advanced phase of lSSc, were found together with signs of inflammation and fibrosis. In advanced dSSc, in the papillary and reticular dermis PNS fibres were reduced and showed relevant ultrastructural alterations. CONCLUSIONS: In SSc, PNS ultrastructure damage is linked to the progression and severity of skin involvement. The alterations evolve from the early to the advanced phase mainly in the diffuse subset. In particular, the severe PNS lesions found in advanced lSSc are already present and widely diffuse in early dSSc and the microvascular involvement in early lSSc seems to precede the modification of the PNS in the skin. Thus, an early therapeutic approach can be useful to reduce the progression of PNS and skin damage in SSc patients.

Adult↗

Unusual manifestations of nervous system Borrelia burgdorferi infection.

Borrelia burgdorferi infection may show disease manifestations in different organ systems, including the skin, heart, central nervous system, peripheral nervous system, and joints. We report two hitherto unknown (to our knowledge) disease manifestations, an arteritis in the central nervous system, and a neuromyopathy of 11 years' duration. Diagnoses were made by demonstrating specific antibodies against B burgdorferi in the cerebrospinal fluid, and elevated specific antibody index. Both patients responded well to treatment, and intrathecal immunologic activity could not be demonstrated after treatment. Serologic analyses (enzyme-linked immunosorbent assay) in serum and cerebrospinal fluid should be performed widely in cases with inflammatory findings in cerebrospinal fluid combined with neurologic disease of unclear origins.

Aged↗

Characterization of hemangioblastomas of spinal nerves.

OBJECTIVE: Hemangioblastoma is classified as a benign tumor of the central nervous system. Peripheral nervous system hemangioblastomas to date have been described only in a few case reports. Experience in treating patients with these rare lesions, which harbor diagnostic and therapeutic pitfalls, is limited. METHODS: To characterize these lesions better, we reviewed our hemangioblastoma database for patients who underwent surgery for extradural hemangioblastoma of the spinal nerve. RESULTS: Between 1983 and 2003, six patients underwent surgery for spinal nerve hemangioblastomas at our institution. These tumors occurred in 2% of all patients with hemangioblastomas of the central nervous system, or 6% of all patients with spinal hemangioblastomas. The occurrence did not differ in von Hippel-Lindau disease cases versus sporadic cases. Radiographically, the tumors easily could be mistaken for schwannomas or metastases; however, they did have some typical features. If a hemangioblastoma was not suspected primarily, profuse bleeding could complicate surgery. Most of the tumors arose from the dorsal sensory fascicles. The vascular supply was from extradural circulation. In general, the surgical outcome of these lesions was good, and permanent neurological deficit was rare. However, local recurrence was observed in three of six patients. CONCLUSION: These tumors harbor diagnostic and therapeutic pitfalls. In general, the tumors are surgically more challenging, and clinically significant bleeding as well as local tumor recurrence is more common than in intradural hemangioblastomas, mostly because of the frequency of incorrect initial radiographic diagnosis. We suggest that because of the surgical consequences, hemangioblastoma should always be considered to be an important radiological differential diagnosis for nerve sheath tumors. Angiography can bring clarification to ambiguous cases.

Adult↗