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Distribution of histamine in the developing peripheral nervous system.

The presence and ontogenetic distribution of histamine was studied in the developing peripheral nervous system of the rat by using an indirect immunofluorescence technique and a specific rabbit anti-histamine antiserum. Histamine immunoreactivity (IR) first appeared in peripheral nerves on embryonic day 14. The number and intensity of histamine-immunoreactive nerves was highest on embryonic days 16-18. During development starting from embryonic day 14, motoneurones in ventral horns of the spinal cord at cervical, thoracic and lumbar levels contained histamine IR. A subpopulation of sensory neurones in dorsal root ganglia exhibited histamine IR. Histamine IR was also present in nerve fibres of ventral and dorsal roots of spinal cord, as well as in spinal nerves. Population of neurons and nerve fibres in sympathetic and pelvic ganglia as well as in myenteric ganglia of the intestine were also labelled with the histamine antiserum. In peripheral target organs, histamine IR was observed in nerve fibres around bronchi of the lungs, in the atria of the heart, in the adrenal gland, in the intestinal wall, in muscular tissues and in subepithelial tissue of the skin. The results of this study indicate that histamine is widely distributed in different types of neurons and nerve fibers of the developing peripheral nervous system.

Animals↗

Deposition of disease-associated prion protein involves the peripheral nervous system in experimental scrapie.

There is some evidence that the peripheral nervous system (PNS) is involved in the pathogenesis of transmissible spongiform encephalopathies (TSEs). The TSE-specific abnormal prion protein (PrP(sc)) is considered as surrogate marker for infectivity. We traced the deposition of PrP(sc) by immunocytochemistry in sheep and hamsters inoculated intraperitoneally with scrapie. The trigeminal, dorsal root, celiac, thoracic, and nodose ganglia contained ganglion cells and fewer satellite cells with prominent granular PrP(sc) deposition. As a novel deposition pattern, punctate deposits in adaxonal location were seen along nerve fibers of peripheral nerve adjacent to ganglia. Such prominent involvement of the PNS in two different experimental scrapie models emphasizes the need to consider the PNS in natural scrapie and other TSEs including bovine spongiform encephalopathy as potential source of infectivity.

Animals↗

[Involvement of the peripheral nervous system in multiple sclerosis].

Multiple sclerosis is a demyelinating disease limited to the central nervous system, but the literature has provided recurring evidence which raises the question of associated peripheral nervous system abnormalities. The prevalence of peripheral neuropathy during multiple sclerosis remains controversial without prospective study. Nevertheless, some data have reported well documented case reports describing the co-occurrence of multiple sclerosis and radiculopathy or mononeuropathy or polyneuropathy in the same patients. By contrast, more frequent subtle nerve abnormalities may be found by using electrophysiological and neuropathological examinations. Some hypotheses have been proposed by Waxman to decipher the electrophysiological and neuropathological findings. The mechanisms for demyelinating disease and peripheral nerve pathophysiology may imply the antigenic properties or the presence of diffusing factors between peripheral nervous system and central nervous system myelin and the molecular plasticity of myelinated fibers.

Antigens↗

Peripheral nervous system functions of workers exposed to n-hexane at a low level.

In order to assess the effects on the peripheral nervous system of n-hexane at a low level, an epidemiological study using a questionnaire, neurological examinations, and neurophysiological studies was carried out on two age-matched groups; one, consisting of 14 exposed workers and the other, of 14 control workers. The 8 h time weighted average of n-hexane concentration in the exposure environment was 58 +/- 41 (mean +/- SD) ppm. In the individual worker, no obvious signs could be found indicating damage to the nervous system that were referable to the n-hexane exposure. On the other hand, when the subjects were taken in groups, the results obtained from the exposed group showed a minor partiality for functional impairment of the peripheral nervous system in many test items. In particular, statistically significant differences between the two groups were detected in the following items: (1) inquiries by questionnaire for persistent or transient symptoms regarding muscle weaknesses and dyesthesia of limbs; (2) the jump test on one foot; (3) the tuning fork test for vibration sensation on the radial processes; (4) the maximal velocity and the residual latency of motor nerve conduction of the posterior tibial nerve. In conclusion, it is not likely that at exposure levels less than the current threshold limit value of 100 ppm proposed by ACGIH, n-hexane may induce clinically overt polyneurophathy. However, there is no gainsaying the possibility that in the exposed workers as a whole, small cumulative effects in the peripheral nervous system may be brought about by long-term n-hexane exposure less than 100 ppm.

Adult↗

Peripheral nervous system involvement in Behçet's disease. Case report and review of the literature.

Central nervous system complication of Behçet's disease are well recognized. However, peripheral nervous system involvement has been rarely observed. A case of Behçet's disease with prominent peripheral nervous system involvement is reported in this article. The results of clinical, electromyographic, immunologic and electron-microscopic findings of a nerve biopsy are presented and discussed in the light of the literature.

Behcet Syndrome↗

Type 2 deiodinase in the peripheral nervous system: induction in the sciatic nerve after injury.

Thyroid hormones are essential for the development and function of the brain and also for the maturation and repair of the peripheral nervous system. In the brain, most of the 3,5,3'-triiodothyronine is locally produced by 5'-deiodination of thyroxine catalyzed by the type 2 deiodinase. The absence of any information about thyroid hormone metabolism in the peripheral nervous system prompted us to study the expression of type 2 deiodinase (mRNA and activity) in the peripheral nervous system. Expression of type 2 deiodinase mRNA was very low in the sciatic nerve of rats until day 5 after birth, then increased from day 10 to 35-45 and gradually decreased afterwards, down to the low basal levels observed in the adult. A lesion of the sciatic nerve in the adult induced an increase in type 2 deiodinase mRNA and activity. After a cryolesion, the stimulation was observed as early as 4 h and mRNA levels increased until 24-48 h, then gradually declined down to basal levels around 28 days, when regeneration and functional recovery were completed. After a permanent transection, up-regulation of type 2 deiodinase persisted in both proximal and distal segments until the end of the experiment (28 days). Transection and cryolesion were also followed by increased type 2 deiodinase mRNA expression in the ipsilateral L4/L6 dorsal root ganglia within 24 h. Both mRNA and activity were found in the peripheral nerve sheaths but not in the internal compartment of the intact or injured nerve. Cultured fibroblasts from the sciatic nerve expressed type 2 deiodinase 4 h after stimulation by 10 microM forskolin, whereas purified Schwann cells did not. The present study provides evidence that the peripheral nervous system has its own system responsible for the local production of 3,5,3'-triiodothyronine, which may play a key role during the regeneration process.

Aging↗

Bovine pancreatic polypeptide-like immunoreactivity in brain and peripheral nervous system: coexistence with catecholaminergic nerves.

The rat central and peripheral nervous system contains a widespread distribution of BPP-like immunoreactive neurons. Some of these neurons coexist with a catecholamine, probably mostly NE. This peptide appears to be releaseable by nerve stimulation. Catecholamine releasing agents such as reserpine do not appear to deplete the BPP. This extensive distribution and unique coexistence of a peptide with peripheral sympathetic nerves suggests a neuromodulatory role of BPP in autonomic functions.

Animals↗

[Syndromes of peripheral nervous system lesions and mechanisms of their formation in disorders of connective tissue].

Systemic rheumatoid diseases are often concomitant with the development of central and peripheral systems pathologies. Presented are the results revealing high frequency of peripheral nervous system lesions (lupus erythematosus and systemic scleroderma), which characterized by polyneuropathy and tunnel syndromes. Based on the results of literature and own studies, pathological mechanisms of peripheral nervous system lesions in diffusion disorders of connective tissue were singled out as follows: ischemic, immunological and metabolic. Taking these mechanisms into account will permit to conduct pathogenetically valid therapy and to improve its results.

Connective Tissue Diseases↗

Mediastinal tumors of peripheral nervous system origin.

A wide spectrum of benign and malignant tumors of peripheral nervous system origin can arise in the mediastinum. These neoplasms are more frequent in the posterior mediastinum and can develop from peripheral nerves, sympathetic and parasympathetic ganglia, and neural tube embryonic remnants. The clinicopathologic features of mediastinal schwannomas, melanotic schwannomas, neurofibromas, ganglioneuromas, granular cell tumors, malignant tumors of peripheral nerve sheath origin, malignant melanocytic tumors of peripheral nerve sheath origin, neuroblastomas, ganglioneuroblastomas, and pigmented neuroectodermal tumors of infancy are reviewed.

Adult↗

[Tumors of the peripheral nervous system in the region of jaw and face].

Benign and malign forms of tumors of the peripheral nervous system also occur in the region of jaw and face. They demonstrate a quite different dignity and different courses. Very well known is the neurofibromatosis (Recklinghausen) which can be observed in several variants in face. The possibility is pointed out that primarily benign tumours of the peripheral nervous system may be degenerated to malign ones and the course as well as the therapy with benign and malign tumours are being described.

Adult↗

Central and peripheral nervous system dysfunction in the clinical variation of Salla disease.

OBJECTIVE: To evaluate the degree of possible peripheral nervous system (PNS) involvement in addition to CNS manifestations in Salla disease, a free sialic acid storage disorder leading to severe mental retardation with a wide clinical variation. BACKGROUND: Salla disease is a lysosomal storage disorder that affects the white matter of the CNS. MRI findings and recent 1H MRS study results provide evidence for delayed central myelination, but there is no previous evidence for PNS involvement in this disease. The gene coding for a presumptive sialic acid transport protein has recently been identified, and the first disease-causing mutations have been characterized. METHODS: Nerve conduction studies; evoked potentials to visual (VEP), brainstem auditory (BAEP), and somatosensory stimuli (SEP); and EEG were carried out on 22 patients (age range 2 months to 57 years) with biochemically and genetically confirmed Salla disease. Brain MRI were available on 14 patients. RESULTS: Nerve conduction studies revealed abnormalities in nearly half of the patients (10/21). The four severely disabled patients and the oldest patient had greatly reduced nerve conduction velocities and prolonged distal latencies compatible with demyelinating polyneuropathy. In addition, SEP was abnormal in the majority of the patients, but VEP and BAEP in only a few cases. PNS involvement was clearly associated with both the phenotypic severity and MRI findings. CONCLUSIONS: The results indicate that dysmyelination in Salla disease occurs not only in the CNS but also in the peripheral nervous system, contributing to the phenotypic variation, which can now be correlated with the molecular basis of the disease.

Adolescent↗

[GM2-Gangliosidosis variant B1 disclosed during adolescence by an isolated multi-systemic involvement of the central and peripheral nervous systems].

The authors report on a Portuguese family with 3 adult brothers affected with GM2-gangliosidosis (B1 variant) in a sibship of 4, and more specifically on one of these brothers with neurological onset at the age of 17. Psychosis, lower motoneuron involvement and dysarthria were predominant in two of the cases; the third had a cerebellar symptomatology. Hexosaminidase A activity, studied in leukocytes, was profoundly deficient when measured using the specific sulfated substrate, but nearly normal using a conventional assay (non-sulfated substrate). These results established the diagnosis of the unusual enzymological form of GM2-gangliosidosis known as the B1 variant, which had so far not been associated with an adult phenotype. Molecular studies are in progress to study genotype/phenotype correlations in this family in comparison with known mutations in the B1 variant and in adult GM2-gangliosidosis. This report also emphasizes that a metabolic etiology, leading to genetic counselling, should be considered in some familial degenerative neurological disorders.

Adolescent↗

Vascular permeability changes in tumours of the peripheral nervous system.

Vascular permeability changes were examined in 34 tumours of the peripheral nervous system by immunohistochemical demonstration of serum proteins as endogenous tracers. The blood-tumour barrier was impaired in the reticular (Antoni type B) portions of neurinomas (Schwannomas) and in cutaneous neurofibromas but was similar to the normal blood-nerve barrier in fibrillary (Antoni type A) neurinomas, in most neurofibromas, in ganglioneuromas and in anaplastic tumours. These differences in permeability are discussed in relation to aspects of pathological tumour vascularization, the histogenesis of microcystic changes, and systemic therapeutic approaches.

Adult↗

[Degeneration and regeneration of the peripheral nervous system with aging].

Clinical and experimental studies have shown that with aging there appear neurological changes which affect both the Central Nervous System (CNS) as well as the Peripheral Nervous System (PNS), bringing about a series of cognitive, sensory and physical disabilities in older people. Nerve lesions also cause disability. The basic mechanisms which begin with lesioned neurons have proved an interesting field of study for many neuroscientists since as far back as the mid-nineteenth century. However the influence of age on these postlesion neuronal processes has not aroused the same level of interest even though many authors have, out of curiosity, published reports of changes which take place in regenerative neurons as a result of age. The progressive increase in the aged population in industrialised nations warrants a detailed study into the influence of age on such neuronal processes. The PNS, due to its accessibility and greater regenerative potential vis-à-vis the CNS, may be a good model for this purpose. From results obtained by both other authors and ourselves it is clear that aging causes a decline in the regenerative abilities of peripheral nerve fibres. Functional recovery is not only slowed down but also decreases with age. The number of regenerative axons and their capacity for end sprouting, together with the biosynthesis and transport of new materials in the regenerative neurons, as well as the proliferation and synthesis of trophic factors by Schwann cells also decay. All of this leads to the fact that the regenerative capacity of nerve fibres is lesser with age, and that functional disabilities after a lesion are greater in older than in younger people.

Aging↗