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A Schenone

Publications and source records attributed to A Schenone.

At least 73 records · Page 4Linked to original sources
PubMed1991

Schwann cell GFAP expression increases in axonal neuropathies.

We studied the Schwann cell (SC) GFAP immunoreactivity in normal human peripheral nerves and in neuropathies of different origin. Immunofluorescence and immunocytochemistry were carried out on serial frozen sections of 58 peripheral nerve biopsies using monoclonal antibodies (mabs) antivimentin and anti GFAP, and antiserum anti S-100 and anti GFAP. To test the specificity of the mabs and antiserum used, proper competition controls on tissue sections of 2 selected cases, tissue cultures studies of human fibroblasts and immunoblotting of homogenates of human fibroblasts, 3 normal and 5 pathologic nerves were carried out. In order to evaluate a possible correlation between SC GFAP positivity and neuropathologic findings a quantitative study was performed, evaluating the SC GFAP reactivity in all the 58 cases, and relating the SC GFAP positivity to the index of nerve pathology (IP) in 9 selected cases, and to the percentage of teased fibers showing axonal degeneration or demyelination and remyelination in 25 representative cases. We demonstrate that in normal human sural nerves and in demyelinating neuropathies only a few scattered SC are recognized by the mabs or antiserum anti GFAP. On the contrary in axonal neuropathies the majority of SC gain the property to express intermediate filaments which show common antigenic properties with GFAP.

Antibodies, Monoclonal↗
PubMed1991

Protective effect of cyproheptadine in a gerbil model of cerebral ischemia.

The efficacy of Cyproheptadine, a serotonin antagonist, in preventing the cerebral ischemic damage was tested on experimental model of transient global cerebral ischemia in Mongolian Gerbil. The semi-quantitative histological evaluation of the severity of ischemic damage showed a protective effect of Cyproheptadine, mainly in the anterior cortical areas.

Animals↗
PubMed1990

[Accuracy of distribution of the doses obtained with electron beams of irregular shape and in the presence of inhomogeneous structures].

The authors have addressed the problem of dose distribution calculation accuracy when irregularly shaped electron beams are used and structural dishomogeneities are present. The mathematical model used for the electrons from the "scattering foil" and from the colimator walls is the "gaussian pencil beam", and the total dose is obtained by adding to the above mentioned components the dose from the electrons diffused by the field defining frame and from bremsstrahlung photons. Depth dose curves, with and without frames, are compared with a satisfactory correspondence between the calculated and the measured curves. The calculation method is considered accurate within 2% of dose and 2 mm in position. When dishomogeneous structures are present and treated as semi-infinite layers, corrections are referred in 2-D to a single anatomical section and can be extended to 3-D if a sufficient number of sections is available for the whole volume definition. However current algorithms need to be improved when there is the possibility to use a much more powerful hardware.

Algorithms↗
PubMed1989

Class II antigen expression on human cultured Schwann cells from patients with Charcot-Marie-Tooth disease.

T lymphocytes control the extent of the immune reaction by recognizing the antigen in connection with class II histocompatibility surface molecules, coded by genes located on the HLA-D locus. The expression of HLA-DR antigens is confined to a few antigen presenting cells, like lymphocytes and macrophages, which can therefore induce the initial phase of the immune reaction. We report that also Schwann cells (SC) from patients with Charcot-Marie-Tooth disease (CMT), an hereditary disorder of the peripheral nervous system, are able to express HLA-DR antigens. Human SC cultures were carried out from sural nerve biopsies of CMT and normal control cases. Cultures were tested on day 7, 14, 21 and 28, with double immunofluorescence technique using rabbit antiserum anti-S-100 and mouse anti-HLA-DR monoclonal antibody. SC from CMT were HLA-DR positive since the first few days, continuing to express class II antigens for all the duration of the culture. The presence of class II antigens on cultured SC from CMT disease suggests that immune-mediated mechanisms may be relevant in the pathogenesis of this degenerative disorder of the peripheral nervous system.

Cells, Cultured↗
PubMed1989

[Hereditary sensory motor neuropathy: degenerative disease or a disease with an immune-mediated pathogenesis?].

The clinical data proving that some hereditary motor-sensory neuropathies (HMSN type 1) are steroid sensitive may indicate inflammatory or immunomediated mechanisms as cofactors contributing to the clinical course of these disorders. The finding of HLA-DR positivity of Schwann cells in HMSN type I along with the presence in some cases of inflammatory infiltrates in nerve sections provides further evidence for this hypothesis.

Autoimmune Diseases↗
PubMed1988

Direct immunofluorescence in sural nerve biopsies.

Direct immunofluorescence (DIF) has been carried out in 66 sural nerve biopsies using antibodies against human IgG, IgA, IgM, C3, C4, albumin, fibrinogen, and kappa- and lambda-chains. In 37 out of 63 (59%) different neuropathies immunoglobulins or other plasma proteins were found within the peripheral nerves. IgM along the myelin sheaths were found in monoclonal IgM-K-associated demyelinating peripheral neuropathy and chronic inflammatory demyelinating peripheral neuropathy. IgM within the perineurium were detected in hereditary, diabetic, paraneoplastic, paraproteinemic and neuropathies of unknown cause. In inflammatory, vasculitic, hereditary and toxic neuropathies fibrinogen, albumin, IgG and IgA were variably observed in endoneurium, endoneurial vessels, perineurium and epineurial vessels. In our experience DIF appears to be just an unspecific marker of sural nerve pathology. In selected cases however DIF may be helpful in the diagnosis or in better understanding the pathogenetic mechanisms of the disease.

Adolescent↗
PubMed1988

HLA-DR Schwann cell reactivity in peripheral neuropathies of different origins.

HLA-DR antigens have been found on Schwann cells in peripheral neuropathies of different origins but not in normal control cases. Class II antigen reactivity was more intense in chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) and hereditary motor and sensory neuropathy type 1 (HMSN), but was also observed in toxic or metabolic neuropathies. The expression of HLA-DR antigen on Schwann cells does not appear to be related to the inflammatory or autoimmune origin of the disease.

Antibodies, Monoclonal↗
PubMed1988

Anti-lymphocyte globulin stimulates normal human T cells to proliferate and to release lymphokines in vitro. A study at the clonal level.

Human peripheral blood mononuclear cells (PBMC) were stimulated in vitro with anti-lymphocyte globulin (ALG), and the phenotypic and functional properties of the blasts obtained were investigated. When stained with monoclonal antibodies (MoAbs), all of the blasts were identified as T cells that expressed predominantly the CD4 phenotype (70% of the cells). The remaining blasts were CD8+. These findings demonstrate that ALG stimulates both helper-inducer and cytotoxic-suppressor cells at random since the CD4 to CD8 ratio in the stimulated blasts was the same as in resting PBMC. This ratio is different from that observed in short-term cultures of T cells stimulated with phytohemagglutinin (PHA) under the same conditions (CD4 to CD8 ratio less than 1). ALG-stimulated T cells were cloned by limiting dilution in the presence of recombinant Interleukin-2 (rIL-2). The clones obtained were expanded and maintained in long term cultures with rIL-2. Thirty-two clones were tested for their capacity of producing colony stimulating activity (CSA) or burst promoting activity (BPA). Twenty-eight of them produced CSA and 12 produced BPA. No correlation was found between the surface phenotype and the ability of the clones to produce CSA or BPA (ie, both the CD4+ and CD8+ clones released the cytokines). When 16 of the same clones were tested for II-2 and gamma interferon (gamma IFN) production, 12 were found to be gamma INF and IL-2 producers. All of the gamma IFN producers also released IL-2, whereas in the single clones no correlation was found with the capacity of releasing BPA and CSA. Supernatants from selected T-cell clones were also tested for hematopoietic growth factor activities in the presence of neutralizing antisera to human granulocyte-macrophage colony stimulating factor (GM-CSF) or to Interleukin-3 (IL-3). It was found that most CSA was attributable to GM-CSF, whereas BPA was mainly related to the presence of IL-3.

Animals↗
PubMed1987

Cerebrospinal fluid and neuropathological study in Devic's syndrome. Evidence of intrathecal immune activation.

Cerebrospinal fluid (CSF) was studied in 2 cases of Devic's syndrome (DS). In one of these cases autopsy was carried out. The main CSF feature in DS is the association of blood-brain barrier damage and intrathecal IgG synthesis. These findings are in keeping with our neuropathological observation of diffuse central nervous system vasculitis and leptomeningitis. As a whole, our CSF and neuropathological findings in DS are consistently different from those in multiple sclerosis.

Albumins↗
PubMed1986

Peripheral neuropathy in Cockayne syndrome.

Two siblings with Cockayne syndrome are reported. In one case a sural nerve biopsy showed a demyelinating peripheral neuropathy with occasional inclusions in Schwann cells made up of electron dense finely granular material intermingled with vacuoles or lamellar structures. The significance, if any, of this accumulated material remains unclear. The presence, in addition, of small finely lamellar intra-axonal osmiophilic bodies suggests an associated axonal involvement.

Child↗
PubMed1986

Complete bilateral relapsing ophthalmoplegia in a diabetic patient with a sensory-motor distal polyneuropathy.

The clinicopathological study of a case of relapsing complete bilateral external ophthalmoplegia associated with a sensory-motor polyneuropathy is presented. No other causes apart from diabetes mellitus were ascertained. The sural biopsy demonstrated an axonal as well as demyelinating neuropathy. The physiopathology of the rare cases of diabetic multiple bilateral cranial nerve palsies is discussed.

Aged↗
PubMed1986

Congenital dyserythropoietic anemia type I: report of a pair of siblings.

Two siblings affected with congenital dyserythropoietic anemia type I are described. They are the sixth familial occurrence reported. Particularly interesting is the comparison between the course and laboratory data of our cases. An unusual finding is the presence of the antigen 'i' on the erythrocytes of both patients.

Anemia, Dyserythropoietic, Congenital↗
PubMed1986

Experimental studies on peripheral nerve repair following early or delayed suture.

Early suture of the sciatic nerve in rats was compared with delayed suture performed after 2 weeks. The distal tract of the nerve was studied morphologically using semifine sections and computerised measurements of the number and diameters of regenerated fibres, and electrophysiologically by the measurement of nerve velocity conduction. The morphological examination did not reveal any substantial difference, while the velocity conduction tests showed better reinnervation following early suture.

Animals↗
PubMed1985

A quantitative and ultrastructural study of substantia nigra and nucleus centralis superior in Alzheimer's disease.

In four patients with presenile Alzheimer's disease (AD) and three age-matched controls a quantitative study of neurons and neurofibrillary tangles (NFT) in the substantia nigra (SN) and nucleus centralis superior (NCS) was performed. A significant neuronal loss, similar in both nuclei, was found in AD cases, while the incidence of NFT was remarkably higher in NCS. Moreover, no significant correlation between neuronal loss and number of NFT was detected. An electron-microscopic study revealed that the subcortical NFT in NCS are made up of paired helical filaments in spite of their globose round shape.

Aged↗
PubMed1985

Polyglucosan bodies in the sural nerve of a diabetic patient with polyneuropathy.

In the sural nerve of a 62-year-old woman with impaired glucose tolerance test and polyneuropathy, many intra-axonal polyglucosan bodies were observed. Polyglucosan bodies have been described in spontaneously or alloxan-diabetic rats, but are not usually observed in human diabetic neuropathy. Since intra-axonal polyglucosan bodies can occur in the sural nerve in various diseases and in aging, they are considered as non-specific changes. Their presence is probably related to a primary axonal neuropathy.

Axons↗