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Biomedical subjects

E Nardelli

Publications and source records attributed to E Nardelli.

At least 19 recordsLinked to original sources

Increased expression of the normal cellular isoform of prion protein in inclusion-body myositis, inflammatory myopathies and denervation atrophy.

The cellular isoform of the prion protein (PrPc) is a glycosylphosphatidylinositol-anchored glycoprotein, normally expressed in neural and non-neural tissues, including skeletal muscle. In transmissible spongiform encephalopathies, or prion diseases, PrPc, which is soluble in nondenaturing detergent and sensitive to proteinase K (PK)-treatment, represents the molecular substrate for the production of a detergent-insoluble and PK-resistant isoform, termed PrP(Sc). In human prion diseases, PrP(Sc) accumulation occurs only in brain tissues, with the exception of new variant Creutzfeldt-Jakob disease, where PrP(Sc) is also detected in lymphoid tissues. Increased amounts of prion protein expression and deposition have been described in pathological muscle fibers of two human muscle disorders, called sporadic inclusion-body myositis (s-IBM) and hereditary inclusion-body myopathy, but it is unknown whether accumulated prion protein reflects normal PrPc or PrP(Sc). We investigated the biochemical characteristics of prion protein in normal human muscle, s-IBM, other inflammatory myopathies and denervation atrophy. We report that 1) both the glycoform profile and size of the normal muscle PrPc are different from those of human brain PrPc; 2) in addition to s-IBM, increased PrPc expression is seen in polymyositis, dermatomyositis and neurogenic muscle atrophy, but PrPc glycoforms are unchanged; 3) only the normal PrPc isoform, and not PrP(Sc), is detected in s-IBM. The present results exclude that s-IBM is a prion disease.

Adult↗

Sympathetic skin response asymmetry in early stage idiopathic Parkinson's disease.

Simultaneous bilateral plantar sympathetic skin response (SSR) was studied in 25 patients with early stage idiopathic Parkinson's disease (IPD), characterized by monolateral motor involvement (Hoehn and Yahr, stage <2) and without clinical evidence of autonomic dysfunctions. Thirteen (mean age: 68.69 +/- 7.70, range 55-76) had extrapyramidal clinical signs only at the left body side, 12 (mean age 66.60 +/- 7.43, range 51-73) at the right body side. A group of 25 healthy, age-matched, subjects were also evaluated. To evoke the responses, trains of 10 electrical pulses were applied at different intensities and frequencies. Only intensities of stimulation > or = 5 times the sensory electrical threshold always assured bilateral plantar responses in all the examined subjects. Amplitude asymmetry between left and right responses was found only in the IPD patients (P < 0.05). The amplitude reduction corresponded to the motor affected side. No analogue latency variation was observed in any group. Independently from the peripheral or central origins of such phenomena, these findings suggest that simultaneous bilateral SSR amplitude evaluation could be useful, in early IPD patients, to demonstrate and to monitor the sympathetic cholinergic dysfunction, despite the lack of autonomic symptoms.

Aged↗

Systemic passive transfer studies using IgM monoclonal antibodies to sulfatide.

We present a patient with benign IgM-gamma anti-Sulfatide (SUL) whose neuropathy was transferred in newborn rabbits. The patient's clinico-pathological picture of anti-SUL-associated demyelinating neuropathy is reported. The monoclonal IgM antibodies prepared by Tatum's method, that retained their biological activity, were passively transferred to newborn rabbits. The passive transfer produced demyelinating nerve lesions very similar to the donor antibody neuropathy. In experimental lesions we observed the human IgM anti-SUL antibodies binding to Schmidt-Lanterman incisures and nodes of Ranvier. We postulate that the myelin-specific and complement-dependent lesions observed in the peripheral nerve support the potential demyelinating role of anti-SUL antibodies. Moreover, the pattern of the antibody binding to the perineuronal sheath of satellite cells in dorsal root ganglia strengthen the hypothesis that anti-SUL antibodies may have a pathogenetic role in this sensorimotor syndrome.

Aged↗

Autoimmune paraneoplastic cerebellar degeneration: immunohistological localization of antibody-binding sites.

Sera from 3 patients with breast or ovarian tumors and paraneoplastic cerebellar degeneration (PCD) contained anti-Purkinje cell antibodies (PCAbs) which also bind to other neurons on frozen sections of adult rodent brain. PCAbs tested on new-born rodent (rabbit, rat, mouse) brain tissue detected only oligodendrocyte-like cells (ODLC) in the white matter and allowed us to speculate on the nature of the antigenic structure in the neuronal cytoplasm. All these PCAbs appear histochemically identical and recognize antigens which belong to so-called "Yo" proteins.

Adenocarcinoma↗

Experimental induction of myelin changes by anti-MAG antibodies and terminal complement complex.

We investigated the role of anti-myelin-associated glycoprotein (MAG) IgM and complement (C) in the pathogenesis of myelin alterations occurring in patients with anti-MAG-associated polyneuropathy. For this purpose, we separately studied the effects of anti-MAG antibodies and terminal C complex (TCC) after injection into the rabbit sciatic nerve. The two different local treatments produced identical ultrastructural abnormalities such as intramyelinic edema, myelin vesiculation and, in particular, separation of the major dense lines with the formation of widely spaced myelin, a peculiar feature encountered in human peripheral nerve disorders with circulating anti-myelin monoclonal IgM. In nerves treated with anti-MAG IgM ultrastructural myelin alterations were concurrent with activation of the rabbit's own C to the formation of TCC. Contrary to the immunological and ultrastructural findings obtained in C-sufficient animals, in C6-deficient rabbits injected with anti-MAG IgM no myelin alterations nor C completion were observed. This study identifies anti-MAG IgM as the mediator and the C as the effector of myelin changes observed in the present model and, for extension, in human neuropathies associated with anti-MAG IgM.

Animals↗

Pattern of nervous tissue immunostaining by human anti-glycolipid antibodies.

Immunostaining of human, bovine and rodent unfixed nervous tissue sections was performed in order to characterize the structures recognized by anti-glycolipid antibodies. Four human sera from patients, two with M-IgM and motor neuron syndrome or motor neuropathy and two with motor neuropathy and polyclonal IgG antibody activity against gangliosides (GL; i.e. GM1, GD1b, GD1a), were utilized. Serum from a patient with sensory neuropathy and M-IgM immunoglobulins with antibody activity against sulfatide (SUL) was included in this series. This study shows that polyclonal and monoclonal anti-glycolipid antibodies give three different patterns of staining. The first is cholera toxin-like showing a more restricted neuronal pattern of staining. The second is peanut agglutinin-like, which includes the carbohydrate epitope shared by a group of glycoproteins in the gray and white matter. The third (anti-SUL) gives a preferential myelin staining. However, sera with anti-GM1 and anti-SUL antibodies recognize a number of closely situated determinants in the gray matter of the spinal cord and in the granule cells, while in peripheral nerves or in neuronal cells in culture their binding produces a different pattern (nodes of Ranvier for anti-GL; myelin for anti-SUL). These findings indicate that immunohistochemistry with anti-GL and anti-SUL antibodies may provide information regarding the glycolipid-bearing anatomical structures as target antigens and further substantiate the role of these molecules in the pathogenesis of autoimmune neurological disorders.

Amyotrophic Lateral Sclerosis↗

Inherited neuroaxonal dystrophy in C6 deficient rabbits.

We report the occurrence of a progressive neurological syndrome clinically characterized by subacute motor neuropathy in offspring of C6 deficient rabbits. On the basis of the pedigree analysis, the disease appears to be genetically transmitted, most probably with an autosomal recessive mode of inheritance. Pathological studies of affected animals revealed: transmitted, most probably with an autosomal recessive mode of inheritance. Pathological studies of affected animals revealed: 1) severe axonal degeneration in the sciatic nerve system involving mainly motor fibers; 2) occasional peripheral axonal enlargement closely associated with axonal degeneration; 3) presence of structured abnormal material in normal-size myelinated fibers of central nervous system (CNS) and peripheral nervous system (PNS); and 4) widespread occurrence of dystrophic axons and axonal spheroids in the gray matter of CNS. By ultrastructural examination, dystrophic axons are filled with tubulovesicular material, stalks of parallel membranes and dense bodies similar to what is described in human neuroaxonal dystrophies (NAD). The disease manifested by C6 deficient rabbits may represent an animal model of primary human NAD.

Animals↗

Complement-mediated demyelination in patients with IgM monoclonal gammopathy and polyneuropathy.

We investigated the role of complement in the pathogenesis of the demyelinating polyneuropathy that occurs in some patients with IgM monoclonal gammopathy. Seven patients with chronic sensorimotor polyneuropathy and IgM monoclonal gammopathy were examined. In six patients, the monoclonal protein recognized an epitope shared by myelin-associated glycoprotein and two peripheral-nerve glycolipids, whereas in one patient, IgM bound to an unidentified myelin antigen. Direct and indirect immunofluorescence and immunoperoxidase assays showed colocalization along the myelin sheaths of peripheral-nerve fibers of monoclonal protein with complement components C1q, C3d, and C5. In addition, terminal-complement complex that was not associated with S protein was detected in myelin sheaths. It appeared that alterations in myelin geometry caused by the separation of myelin lamellae corresponded to sites at which terminal-complement complex was deposited. We conclude that demyelination in polyneuropathy associated with IgM monoclonal gammopathy may be mediated by complement.

Aged↗

Motor neuron syndrome and monoclonal IgM with antibody activity against gangliosides GM1 and GD1b.

We demonstrated that an IgM M-protein from a patient with motor neuron syndrome had antibody activity against gangliosides GM1, GD1b, and asialo GM1. Studies with a sugar-binding lectin suggested that the epitope in the patient's M-IgM involved the Gal(beta 1-3) GalNAc moiety. Immunohistological techniques demonstrated staining of axons in the lumbar roots, granular cells, and white matter in the cerebellum by the patient's M-IgM. We propose that, in this case, an autoimmune mechanism of motor neuron syndrome associated with a monoclonal protein is most likely.

Antibodies, Monoclonal↗

Polyneuropathy in hypereosinophilic syndrome.

We investigated two patients with the idiopathic hypereosinophilic syndrome and peripheral neuropathy. Clinical, EMG, and pathological findings were consistent with axonal polyneuropathy. Morphologic changes of the nerve biopsies suggested axonal damage secondary to increased endoneurial pressure from leakage of capillaries. We postulate that endothelial cell damage, followed by nerve edema, is the first step in the pathogenesis of peripheral neuropathy in these patients.

Biopsy↗

Binding of monoclonal anti-myelin-associated glycoprotein antibodies to human foetal peripheral neurons in culture.

Dorsal root ganglion cells, obtained from 8-10-week human foetuses, were isolated by enzymatic procedure and grown on poly-L-lysine-coated coverslips. Most of the cultured cells showed the ultrastructural and immunological features of normal peripheral neurons. By immunocytochemistry neurons reacted with IgM antibodies with specificity for myelin-associated glycoprotein (MAG) from patients affected with IgM k gammopathy and peripheral neuropathy. The antigen was located on the plasmalemma of both perikarion and axon. We suggest that anti-MAG antibodies do not recognize neuronal MAG, but rather an epitope shared with different glycoproteins.

Antibodies, Monoclonal↗

Poor graft function associated with graft-versus-host disease after allogeneic marrow transplantation.

This is a retrospective analysis of marrow function in 171 recipients of an HLA-matched bone marrow transplant (BMT). Only patients with detectable hemopoiesis as indicated by leukocyte counts greater than 1.0 x 10(9)/l and platelet counts greater than 25 x 10(9)/l who were alive on day 30 were entered in the study. Poor marrow function was detected in 24 (14%) patients as indicated by a decrease in the peripheral blood counts to less than 40% of the maximal preceding values post-transplant in association with reduced marrow cellularity. Leukopenia (n = 4), thrombocytopenia (n = 3) or a combination of the two (n = 17) occurred 62 +/- 23 (SEM) days post-transplant and was associated with acute graft-versus-host disease (AGVHD) grade II or more and infection (n = 19) in the absence of clear rejection or persistence/recurrence of malignant disease. A multivariate analysis showed that AGVHD was the major risk factor (p = 0.001) for developing poor graft function. In the 24 patients with poor graft function, hemopoietic recovery was strongly associated with resolution of AGVHD and of infections. Their survival (27%) was the same as survival for other patients matched for GVHD who had no pancytopenia. The causes of death were GVHD (n = 13), pneumonia (n = 3) and infections (n = 1). This study draws attention to a particular type of poor graft function following allogeneic BMT that is characterized by (1) normal timing and quality of engraftment, (2) AGVHD of grade II or greater, (3) progressive and severe pancytopenia, and (4) multiple infections with poor clinical condition.(ABSTRACT TRUNCATED AT 250 WORDS)

Anemia, Aplastic↗