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Biomedical subjects

Margherita Capasso

Publications and source records attributed to Margherita Capasso.

6 recordsLinked to original sources

Experimental axonopathy induced by immunization with Campylobacter jejuni lipopolysaccharide from a patient with Guillain-Barré syndrome.

New Zealand white rabbits were immunized with a lipopolysaccharide (LPS) extracted from a Campylobacter jejuni HS:19 strain isolated from a GBS patient expressing GM1 and GD1a-like epitopes, Freund's adjuvant (group I) and Freund's adjuvant plus keyhole lympet hemocyanin (KLH) (group II). Both groups showed high titers of anti-LPS and anti-GM1 and lower titers of anti-GD1b and anti-GD1a antibodies. Weakness and axonal degeneration in sciatic nerves was detected in 1/11 of group I and 6/7 of group II. This model replicates, at least in part, the pathogenetic process hypothesized in the human axonal GBS with antiganglioside antibodies post C. jejuni infection and indicates that KLH plays an additional role in neuropathy induction.

Animals↗

Lewis-Sumner syndrome in hepatitis C virus infection: a possible pathogenetic association with therapeutic problems.

A patient with chronic hepatitis from hepatitis C virus (HCV) infection developed Lewis-Sumner syndrome (LSS). The neuropathy worsened after intravenous immunoglobulins, remitted after intravenous methylprednisolone, relapsed during interferon-alpha, but responded again to steroids continued for 68 weeks with clinical remission and without worsening of hepatitis. We are not aware of other reports of HCV infection and LSS. This association may be coincidental or related to a virus-triggered immune-mediated process. Although the coexistence of a dysimmune neuropathy with hepatitis makes problematic the choice of treatment, we emphasize that the patient's condition during treatment with steroids and the 46 following weeks without therapy has been excellent.

Adult↗

Familial idiopathic hyper-CK-emia: an underrecognized condition.

Persistent elevation of serum creatine kinase (CK) in individuals with normal neurological and laboratory examinations has been called idiopathic hyperCKemia (IH). IH has been reported in rare families and was recently ascribed to caveolin-3 gene mutations. We retrospectively found that IH was familial in 13 of 28 subjects in whom serum CK was measured in relatives. These 13 families had a total of 41 subjects with IH, including six over 60 years of age. In eight families there was male-to-male transmission and a higher prevalence of males with hyperCKemia. Muscle biopsy in one member of all families was normal or showed minimal, nonspecific changes. Morphometric examination disclosed different patterns of changes in fiber size and distribution. Caveolin-3 expression was normal and in five families molecular genetics excluded caveolin-3 gene mutations. Our findings suggest that IH is familial in 46% of cases. Familial IH is a benign genetically heterogeneous condition that is autosomal-dominant in at least 60% of cases, with a higher penetrance in men.

Adolescent↗

Zinc dyshomeostasis: a key modulator of neuronal injury.

Zn2+ is a potently toxic cation involved in the neuronal injury observed in cerebral ischemia, epilepsy, and brain trauma. Toxic Zn2+ accumulation may result from either trans-synaptic Zn2+movement and/or cation mobilization from intracellular sites. To gain entry to the cytosol, Zn2+ can flux through glutamate receptor-associated channels, voltage-sensitive calcium channels, or Zn2+-sensitive membrane transporters, while metallothioneins and mitochondria provide sites of intracellular Zn2+ release. Intracellular Zn2+ homeostasis is sensitive to patho-physiological environmental changes, such as acidosis, inflammation and oxidative stress. The mechanisms by which Zn2+ exerts its neurotoxicity include mitochondrial and extra-mitochondrial production of reactive oxygen species and disruption of metabolic enzymatic activity, ultimately leading to activation of apoptotic and/or necrotic processes. Beside acute neuronal injury, an exciting new area of investigation is offered by the role of Zn2+ dysmetabolism in Alzheimer's disease as the cation acts as a potent trigger for Abeta aggregation and plaque formation. Finally, recent findings suggest that alteration of Zn2+ homeostasis might also be a critical contributor to aging-related neurodegenerative processes. Thus, multiple evidence suggest that modulation of intracellular and extracellular Zn2+ might be an important therapeutical target for the treatment of a vast array of neurological conditions ranging from stroke to Alzheimer's disease.

Alzheimer Disease↗

Can electrophysiology differentiate polyneuropathy with anti-MAG/SGPG antibodies from chronic inflammatory demyelinating polyneuropathy?

OBJECTIVES: Patients with polyneuropathy and antibodies to myelin-associated glycoprotein (MAG) and sulphated glucuronyl paragloboside (SGPG) differ from chronic inflammatory demyelinating polyneuropathy (CIDP) because of a slower, progressive course, symmetrical and predominantly sensory involvement of legs, predominantly distal slowing of motor conductions, and poorer response to therapy. We studied whether a wide set of electrophysiologic parameters may differentiate these two neuropathies. METHODS: We reviewed the electrophysiological studies of 10 patients with anti-MAG/SGPG antibodies and 22 with CIDP examining: (1) motor conduction velocity and distal compound muscle action potential amplitude; (2) conduction block (CB) and temporal dispersion; (3) distal motor latency and terminal latency index (TLI); (4) F wave and proximal conduction time; and (5) sensory conduction and occurrence of abnormal median with normal sural sensory potential. RESULTS: Anti-MAG/SGPG neuropathies showed: (1) more severe involvement of peroneal nerves; (2) more frequent disproportionate distal slowing of motor conductions (TLI< or =0.25) and absent sural potential, and (3) no CB. However 3/22 CIDP patients also had at least two nerves with TLI< or =0.25 and no CB. CONCLUSIONS: Electrophysiologic findings suggest in anti-MAG/SGPG neuropathy a length-dependent process with a likely centripetal evolution. A disproportionate slowing of conduction in distal segments of motor nerves suggests the diagnosis of anti-MAG/SGPG neuropathy, although it is not pathognomonic.

Adult↗