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Biomedical subjects

R Nemni

Publications and source records attributed to R Nemni.

At least 55 records · Page 3Linked to original sources
PubMed1993

Serum antibodies to Purkinje cells and dorsal root ganglia neurons in sensory neuronopathy without malignancy.

Anti-Purkinje cell antibodies (APCA), believed to be markers of paraneoplastic cerebellar degeneration in females, have been identified in the serum of 3 men with subacute sensory neuronopathies and no evidence of tumors 5 years after the onset of the neurological signs. By indirect immunohistochemistry on sections of rat cerebellum and dorsal root ganglia, the patients' IgG bound to the cytoplasms of both Purkinje cells and dorsal root ganglia neurons. By western blot analysis on whole human cerebellum and whole human dorsal root ganglia homogenates, the IgG from 2 patients bound to a 62-kd protein in both homogenates and the IgG from 1 patient bound to a 110-kd protein in the cerebellum homogenate only. Yo autoantibody test was negative in all patients. Our study provides evidence that non-anti-Yo APCA may be associated with subacute sensory neuronopathies and are not necessarily markers of an underlying tumor. The previously described anti-Yo APCA has only occurred in females with cancer.

Aged↗
PubMed1993

Acute presentation of Tangier polyneuropathy: a clinical and morphological study.

We describe a patient with Tangier disease and a peripheral neuropathy with an unusual acute onset. The morphological studies of sural nerve biopsy revealed both axonal degeneration and demyelination, and the fiber loss was preferentially restricted to two of ten nerve fascicles. The cytoplasm of Schwann cells, fibroblasts, macrophages and pericytes were vacuolated because of the presence of numerous lipid droplets. The clinical and morphological findings are consistent with the possibility that ischemia plays a major role in causing this neuropathy.

Female↗
PubMed1993

Bilateral eighth cranial nerve neuropathy in human immunodeficiency virus infection.

A 21-year-old HIV-1 seropositive African man developed an acute febrile illness followed by a sudden sensorineural bilateral hearing loss. Neurophysiological studies demonstrated the bilateral involvement of both branches of the vestibulocochlear cranial nerves. Immunological studies revealed the presence of an ongoing central nervous system HIV-1 infection. A sural nerve biopsy showed the presence of inflammatory cells. We suggest HIV testing for all cases of sudden onset of bilateral hypoacusia.

Acquired Immunodeficiency Syndrome↗
PubMed1993

Antibodies to sulfatide and to chondroitin sulfate C in patients with chronic sensory neuropathy.

Sera from eight of 25 patients with chronic sensory neuropathy had high titers of antibodies to sulfatide and chondroitin sulfate C or both. Preclearing of patients' sera with either sulfatide or chondroitin sulfate C revealed that in four patients the antisulfatide antibodies crossreacted with chondroitin sulfate C. By indirect immunohistochemistry sera reactive to sulfatide only had a different staining pattern from those reactive to both sulfatide and chondroitin sulfate C. By direct immunohistochemistry we found immunoglobulins bound to nerve fibers only in patients with serum antibodies against both sulfatide and chondroitin sulfate C. Our study provides evidence that antibodies to sulfatide and to chondroitin sulfate C differ in their fine specificity and are present in 30% of patients with chronic sensory neuropathy.

Adult↗
PubMed1993

Effect of hypothyroidism on rat peripheral nervous system.

The function and structure of the peripheral nervous system of Sprague-Dawley rats, 3 months after the induction of hypothyroidism by administration of N-propylthiouracil in drinking water, has been studied. The motor action potential amplitude of the caudal nerve showed a significant reduction (p < 0.001) when compared with an age-matched control group of animals. Computer-assisted morphometric analysis of sciatic nerves of hypothyroid rats showed normal distribution and density of myelinated fibers, and a normal axon/myelin ratio. Electron microscopy revealed only minor alterations in axons of myelinated fibers characterized by a dissolution of neurotubules. After two months of substitution therapy these effects were reversed. The present data suggest that early impairment of nerves induced by hypothyroidism is rare and could be related to metabolic alterations rather than to structural changes and is reversible with hormone treatment.

Action Potentials↗
PubMed1993

Lambert-Eaton myasthenic syndrome and polyneuropathy in a patient with epidermoid carcinoma of the lung.

We describe a patient affected by the Lambert-Eaton myasthenic syndrome, sensory motor axonal neuropathy and epidermoid carcinoma of the lung. Serum autoantibodies to voltage-operated calcium channels were detected. After lobectomy, voltage-operated calcium channel-related structures were demonstrated in the patient's tumor. By immunocytochemistry, the patient's IgG reacted with neural structures and particularly with intermediate filaments. We think that these autoantibodies may be implicated in the pathogenesis of the neurological symptomatology.

Aged↗
PubMed1992

Effect of chronic treatment with recombinant interleukin-2 on the central nervous system of adult and old mice.

We have studied the effects of chronic treatment with recombinant interleukin-2 on the central nervous system of adult and old mice. Treatment with high doses of recombinant interleukin-2, on a schedule similar to that used in humans, was started at the age of 4 and 17 months, respectively, and ended 3 months later. At that time, all the mice were tested for acquisition of a passive-avoidance task and then sacrificed for histological examination. Three of the four groups (treated and control adults and control old mice) did not differ from one another in task performance or neuron density in frontal cortex, cerebellum, dentate gyrus or CA1-2, CA3, CA4 hippocampal areas. The old treated mice were unique in showing impairment of the mnesic functions and marked neuronal cell loss and degenerative changes limited to the hippocampal regions. Immunohistochemical studies did not show any significant amount of immunoglobulins in affected areas. Our results suggest that in old mice the impairment of the mnesic functions after recombinant interleukin-2 administration is due to hippocampal neuronal damage.

Aging↗
PubMed1992

IgG monoclonal proteins from patients with axonal peripheral neuropathies bind to different epitopes of the 68 kDa neurofilament protein.

We describe three patients with a sensorimotor axonal polyneuropathy and an IgG M-protein that binds to a 68 kDa axonal protein identified as the low molecular weight neurofilament protein (NF-L). The immunological studies revealed that the M-proteins have different target epitopes: one is phosphorylated and the other two are nonphosphorylated. One of the nonphosphorylated epitopes is common to other intermediate filaments, such as desmin and vimentin.

Axons↗
PubMed1992

In vivo modulation of myelin gene expression by human recombinant IL-2.

We treated adult mice with human recombinant interleukin-2 (IL-2) and determined the expression of the genes encoding for the major central and peripheral myelin proteins. In the CNS, myelin basic protein (MBP) and myelin-associated glycoprotein (MAG) mRNA levels were the same both in IL-2-treated and in control mice. Proteolipid protein (PLP) transcript was decreased in IL-2-treated animals when compared to controls. In the PNS, the messages for the glycoprotein P0 and for MBP were markedly increased in IL-2-treated animals when compared to controls.

Animals↗
PubMed1992

A clinical, electrophysiological, morphological and immunological study of chronic sensory neuropathy with ataxia and paraesthesia.

We have observed 9 patients (8 men and 1 woman), 58 to 77 years of age with neuropathy with only sensory symptoms and insidious onset. Five of them (4 men and 1 woman) aged 65 to 77 years, had normal serum electrophoretic profiles, while the others (all men), 58 to 74 years, had IgM monoclonal gammopathy of undetermined significance (MGUS). Clinical data were consistent with a sensory neuropathy affecting predominantly the kinesthetic sense (position and vibration sensation). The electrophysiological data indicated predominant sensory axonal neuropathy. Morphological data confirmed the primary axonal damage. Western immunoblot showed that the IgG from a patient without MGUS reacted with a 55 kD protein of dorsal root ganglion homogenate. Three of four patients with IgM MGUS were serum reactive against chondroitin sulfate C (ChS-C) in double immunodiffusion. After absorption with ChS-C the monoclonal peak completely disappeared from two patients and was decreased in the third patient. Our data indicate that immunological abnormalities are part of the pathogenesis for a subgroup of chronic neuropathy with only sensory symptoms.

Aged↗
PubMed1991

Muscle fibre type and habitual snoring.

Although anatomical abnormalities of the upper airway have been recorded in some patients with obstructive sleep apnoea (OSA), a muscle tone dysregulation also seems to have an important role in this disorder. Since habitual snoring is the initial stage of OSA, the structural characteristics of upper airway muscles (medium pharyngeal constrictor muscle [MPCM]) from 13 men (9 non-snorers and 4 habitual snorers) were studied. MPCM fibre structure in non-snorers was broadly similar to that in normal limb muscles, with the exception that fibre diameters were smaller for all fibre types. Compared with limb muscles, MPCM had a smaller proportion of type IIb fibres and a higher proportion of types I and IIa fibres. MPCM in habitual snorers had an abnormal distribution of fibre types (low percentage of type I and type IIb fibres and high percentage of type IIa fibres) compared with non-snorers (p less than 0.001) and the type IIa fibres were hypertrophic. No myopathic or neurogenic changes were seen. Two possible hypotheses explain the abnormal distribution of fibre types in snorers. First, a constitutionally determined reduction of slow alpha-motor neurons induces an adaptive transformation of type IIb to type IIa fibres and a hypertrophy of type IIa fibres; or, second, motor neurons change their patterns of discharge and, hence, of activation, and modify fibre-type distribution of MPCM as an adaptation to the anatomical characteristic of upper airway and habitual snoring.

Adult↗
PubMed1991

Polyneuropathy associated with IgA monoclonal gammopathy: a hypothesis of its pathogenesis.

We describe three patients with chronic progressive polyneuropathy associated with IgA monoclonal gammopathy. Two patients had a prominent sensory neuropathy and one had a prominent motor neuropathy. Sural nerve biopsies showed axonal degeneration in all cases. In immunocytochemical studies patients' IgG immunostained axons. By Western immunoblot a band of IgG reactivity with an axonal protein of 66 kDa was found. No band of IgA and IgM were found. We suggest the possibility that the IgA monoclonal protein may act as a stimulating factor of preexisting B cell clones eliciting an immune reaction against nerve antigens.

Aged↗
PubMed1991

Early detection of skin and muscular involvement in Lafora disease.

Two siblings with Lafora disease (LD) are described: one with epilepsy, myoclonus, EEG abnormalities, severe dementia and many Lafora bodies (LBs) in muscle and skin tissue; the other with myoclonus, epilepsy, EEG abnormalities and LBs in muscle and in skin tissue, without dementia. The findings suggest that the diagnosis of LD by skin and muscular biopsy is possible in the early stage of the disease, when there are myoclonic epilepsy and EEG abnormalities, before the onset of dementia.

Adolescent↗
PubMed1991

Axonal neuropathy in a patient with monoclonal IgM kappa reactive with Schmidt-Lantermann incisures.

We report a patient with a progressive, predominantly sensory neuropathy and a IgM kappa M-protein that binds to Schmidt-Lantermann incisures. A sural nerve biopsy showed primary axonal damage and IgM deposits at Schmidt-Lantermann incisures were seen by direct immunoperoxidase. Serum from the patient injected into rat sciatic nerve reacts with the incisures as with those in the patient's nerve. The IgM kappa M-protein reacts with chondroitin sulfate C and binds to a broad nerve protein band with a mobility of between 170 and 118 kDa. Peripheral neuropathy may be related to the M-protein, which had immunocytochemical reactivity not previously described for patients with polyneuropathy and IgM monoclonal gammopathy.

Axons↗
PubMed1991

[Autoimmune neuropathy in monoclonal gammopathy].

The relationship between polyneuropathies and monoclonal gammopathies is well known even though the pathogenetic hypotheses are controversial. The role of autoantibodies against neural antigens has been recently underlined. 45 patients (29 M and 16 F), affected by multiple myeloma (MM) non-Hodgkin lymphoma (NHL) with paraproteinemia and monoclonal gammopathies of undetermined significance (MGUS)4, underwent an EMG study including SCV, MCV and late responses of several nerves, and a search for serum antibodies against neural antigens by immunoblotting assay. 19 out of 45 pts. tested positive to EMG and 15 out of 45 (10 MM and 5 NHL) showed a serological positivity. Among them 11 were positive to EMG too. The results confirm the hypothesis of a possible pathogenetic role of high-titer autoantibodies against neural antigens in cases of polyneuropathy.

Adult↗