Search results for "peripheral nervous system"
showing 10 items of 90 documents
Effects of nicotine receptor agonists on acetylcholine release from the isolated motor nerve, small intestine and trachea of rats and guinea-pigs
1992
The effects of nicotine receptor agonists on the release of [3H]acetylcholine from the phrenic nerve, the small intestine and the trachea were investigated to characterize neuronal nicotine receptors within the peripheral nervous system. Contraction of the indirectly-stimulated hemidiaphragm was recorded to investigate desensitization of the postsynaptic muscular nicotine receptors. Nicotine, cytisine, 1,1-dimethyl-4-phenylpiperazinium and 2-(4-aminophenyl)-ethyl-trimethyl-ammoniumiodide caused a concentration-dependent (0.1-30 microM) increase in evoked [3H]acetylcholine release from the phrenic nerve, whereby bell-shaped concentration-response curves were obtained. The rank order of decre…
The neuro-B cell link of peptidergic innervation in the Bursa Fabricii
1991
The Bursa Fabricii, restricted to birds, specifically provides the microenvironment for B-cell maturation. The presence of nerve fibers containing immunopotent neuropeptides in immune organs opens interesting perspectives on the understanding of neuroimmune communication. As an organ for the development of only B-lymphocytes is not known in mammals, the contribution of a peptidergic innervation to the microenvironment of B-cells is not known. Therefore, we studied the peptidergic innervation of the Bursa Fabricii as an organ of B-cell maturation. Four different neuropeptides were found in nerve fibers of the Bursa Fabricii: tachykinins (TK), vasoactive intestinal peptide (VIP), galanin (GAL…
Study of neurinomas with ultrasound contrast media: review of a case series to identify characteristic imaging patterns
2011
The aim of this study was to evaluate whether there exists a characteristic distribution pattern of vessels within neurinomas that may be used to characterise this type of lesion by employing a contrast-specific ultrasound technique.Between January 2003 and May 2010, 66 suspected neurinomas were evaluated according to their sonographic features (solid fusiform mass with well-defined margins located in direct continuity with the nerve that was not always discernible and heterogeneous as a result of the presence of small cystic areas or calcifications). The lesions were examined using a sonographic contrast medium consisting of sulphur hexafluoride microbubbles and equipment with dedicated co…
Neuropathic pain. Redefinition and a grading system for clinical and research purposes.
2008
Pain usually results from activation of nociceptive afferents by actually or potentially tissue-damaging stimuli. Pain may also arise by activity generated within the nervous system without adequate stimulation of its peripheral sensory endings. For this type of pain, the International Association for the Study of Pain introduced the term neuropathic pain, defined as "pain initiated or caused by a primary lesion or dysfunction in the nervous system." While this definition has been useful in distinguishing some characteristics of neuropathic and nociceptive types of pain, it lacks defined boundaries. Since the sensitivity of the nociceptive system is modulated by its adequate activation (e.g…
Association of human herpesvirus 6 and human herpesvirus 7 with demyelinating diseases of the nervous system.
2001
Peripheral blood mononuclear cells and plasma of 113 patients with neurological disorders and 150 blood donors were analyzed for HHV-6 and HHV-7 sequences by PCR. The prevalence of HHV-6 was significantly higher in patients with multiple sclerosis (P < 0.01) than in cases of nondemyelinating diseases of the central and demyelinating diseases of the peripheral nervous systems and blood donors. HHV-6 viremia was found only in patients with multiple sclerosis, predominantly in the active phase of the disease. A significantly higher frequency of HHV-7 reactivation in patients with demyelinating diseases of the peripheral nervous system suggests also its association with demyelinating processes.
Secondary tactile hypoesthesia: a novel type of pain-induced somatosensory plasticity in human subjects
2004
Quantitative sensory testing revealed that pain induced by intracutaneous capsaicin injection elicited secondary hyperalgesia coexisting with secondary tactile hypoesthesia. Mapping the areas of altered mechanical sensations adjacent to the capsaicin injection disclosed that the area of secondary hyperalgesia was always nested in a larger area of secondary hypoesthesia easily detected as numbness by most subjects. Psychometric functions revealed a twofold rightward shift of tactile detection (hypoesthesia), which coexisted with a more than fourfold leftward shift of pricking pain detection (hyperalgesia) in the same skin area. As a mechanism we propose a functional switch at the spinal leve…
Analysis of F-wave in metabolic neuropathies: a comparative study in uremic and diabetic patients.
1987
Motor nerve conduction study along the entire length of the ulnar and tibialis posterior nerves was carried out in 30 diabetics compared with 30 uremic patients and 30 control subjects. The conduction in the proximal and the distal nerve segments was evaluated by the determination of the M and F latencies, MNCV (between the stimulus sites), FWCV (between the spinal cord and the stimulus sites), and F-ratio (conduction time ratio of proximal to distal segment). In both groups of patients the lower limbs appear much more involved than the upper, where the ulnar nerve is more commonly affected in uremic than in diabetic patients. In diabetic neuropathy the motor conduction abnormalities are di…
Voila, a New Drosophila Courtship Variant that Affects the Nervous System: Behavioral, Neural, and Genetic Characterization
1998
InDrosophila melanogaster, a specificPGAL4transposon induces theVoila1genetic variant and produces multiple phenotypes. HomozygousVoila1/1flies rarely reach adulthood, whereas heterozygousVoila1/+adult males show strong bisexual behavior. Males with a single copy ofVoila1driving the feminizing transgeneUAS-transformershow very reduced sexual activity but no overall effect on their behavior.Voila1is specifically expressed in the nervous system. In the CNS, it is expressed mainly in the mushroom bodies and, to a lesser extent, in the antennal lobes. In the peripheral nervous system, GAL4 expression is almost entirely restricted to the gustatory sensilla. Using chromosomal deficiencies, the be…
Hsp60 Friend and Foe of the Nervous System
2019
Hsp60 belongs to the subgroup of molecular chaperones named chaperonins and, typically, resides and functions in the mitochondria but it is also present in extramitochondrial sites. It chaperones client peptides as they fold to achieve the native conformation and also displays anti-stress roles by helping stress-damaged proteins regain a functional shape. Thus, Hsp60 is central to the integrity and functionality of mitochondria and energy production. All cells in the nervous system depend on Hsp60 so when the chaperonin malfunctions the consequences on nervous tissues are usually devastating, causing diverse diseases. These are the Hsp60 chaperonopathies, which can be genetic or acquired wi…
Peripheral Neuropathy in the Hypereosinophilic Syndrome: A Case Report
1989
We observed a patient with the hypereosinophilic syndrome that showed as a prominent clinical feature peripheral nerve dysfunction. The neuropathy evolved over 4 months and affected sensory and motor functions. Nerve conduction studies and EMG were compatible with axonal neuropathy. Nerve and muscle biopsies revealed severe axonal degeneration with neurogenic atrophy of muscle. Morphometry of peroneal nerve showed marked axonal loss, more prominent in large myelinated fibers. There was no evidence of vasculitis process. Neuropathy is produced by eosinophil-released substances exerting a neurotoxic effect through direct altered vascular endothelial permeability and local mast cell histamine …