Biomedical subjects

E Scarpini

Publications and source records attributed to E Scarpini.

At least 37 records · Page 2Linked to original sources

PubMed1998

Cultured human monocytes release proinflammatory cytokines in response to myelin basic protein.

In human cultured monocytes we examined the ability of myelin basic protein (MBP) to induce the production of proinflammatory cytokines potentially involved in inflammatory demyelination. Northern blots and specific immunoassays demonstrated that monocytes incubated with optimal doses of MBP showed increased mRNA expression and release of tumor necrosis factor (TNF-alpha), interleukin-1beta (IL-1beta), interleukin-6 (IL-6), interleukin-8 (IL-8) but not of interleukin-12/p40 (IL-12/p40). We also showed that cytokine production by MBP-stimulated monocytes was abrogated by incubation with Dexamethasone. These data suggest that interaction of mononuclear phagocytes with MBP may participate in the regulatory process of cytokine production during inflammatory demyelination and support the beneficial role of corticosteroids therapy in aberrant immune responses to the myelin sheath.

Animals↗

PubMed1998

Fatal familial insomnia: genetic, neuropathologic, and biochemical study of a patient from a new Italian kindred.

Fatal familial insomnia (FFI) is an inherited prion disease linked to a mutation at codon 178 of the PRNP gene that results in aspartic acid to asparagine substitution, in coupling phase with methionine at position 129. The disease is characterized clinically by insomnia with disturbances of the autonomic, endocrine, and motor systems and neuropathologically by selective degeneration of the thalamus. Phenotypic variability is well known and has been linked to homozygosity or heterozygosity at PRNP codon 129. We report the clinical, neuropathologic, and biochemical findings and genomic analysis of a patient with FFI from a new Italian kindred. Although homozygous for methionine at codon 129, this patient showed some clinical and pathologic features most commonly found in heterozygotes.

Blotting, Western↗

PubMed1997

Immunocytochemical expression of human muscle cell p75 neurotrophin receptor is down-regulated by cyclic adenosine 3',5'-monophosphate.

To investigate whether the immunocytochemical expression of low affinity neurotrophin receptor (p75) in human muscle is modulated by increased levels of intracellular cyclic adenosine 3',5'-monophosphate (cAMP), human cultured myogenic cells were treated with cAMP analogues dibutyryl cAMP (dbcAMP 0.5-1 mM) and 8-bromo cAMP (1 mM) or the adenylate cyclase activator forskolin (10-100 microM). Cultures were processed for indirect immunofluorescence microscopy using an anti-human p75 mAb. The treatment of cultured muscle cells with cAMP analogues or forskolin for two days induced a decrease of immunoreactivity for p75 and a reduction of both myotube formation and morphological cell differentiation. Removal of cAMP derivatives from the medium resulted in a return of immunoreactive cells to the levels of untreated controls. These data indicate that adenylate cyclase is involved in the regulation of human muscle p75.

Adenylyl Cyclases↗

PubMed1997

p75 neurotrophin receptor induction and macrophage infiltration in peripheral nerve during experimental diabetic neuropathy: possible relevance on regeneration.

In this study we examined the expression of the neurotrophin receptor p75 (p75NTR) and the activation of macrophages in the sciatic nerve of rats at different time points after the induction of diabetes with streptozotocin (STZ). Northern blot and immunocytochemical analysis showed that p75NTR was not detectable in the sciatic nerve by Week 2 after STZ treatment. At this time, single nerve fiber immunostaining using ED1 monoclonal antibody revealed that active macrophages were infiltrating the endoneurium, which had a normal morphological aspect. By Weeks 5 and 15 p75NTR mRNA and protein were induced in the endoneurium of diabetic animals. Immunocytochemical analysis of teased single nerve fibers showed that p75NTR protein was distributed uniformly along isolated fibers with no pathological evidence of axonal degeneration or myelin disruption. At this time, cells of the phagocyte lineage had already disappeared from the nerve. These data show that during experimental diabetic neuropathy, the endoneurial induction of p75NTR is localized along isolated nerve fibers showing no morphological alterations, and in time, follows the recruitment of active macrophages in the nerve, suggesting that these cells, directly or through their products, can influence p75NTR induction. This process might play an important role in STZ diabetic neuropathy, as a response to decreased levels of neurotrophins such as NGF and promoting nerve regeneration in the early phases of the disease.

Animals↗

PubMed1997

Effect of acetyl-L-carnitine in the treatment of painful peripheral neuropathies in HIV+ patients.

We studied the effects of acetyl-L-carnitine on pain in 16 HIV+ patients affected by painful distal symmetrical neuropathy. Patients were treated with 0.5-1 gr per day of acetyl-L-carnitine either i.m. or i.v. for 3 weeks. Pain intensity was measured before and after the treatment by the Huskisson's analogic scale. Ten patients (62.5%) reported an improvement of symptoms, five patients (31.25%) were unchanged, one patient worsened. The results of this open study show that acetyl-L-carnitine can have a role in the treatment of pain in distal symmetrical polyneuropathy related to HIV infection. However, further double-blind, placebo-controlled studies are needed to confirm these preliminary results.

Acetylcarnitine↗

PubMed1996

In situ hybridization study of myelin protein mRNA in rats with an experimental diabetic neuropathy.

Distribution of protein zero (P0) and myelin basic protein (MBP) mRNAs in the sciatic nerve from rats with alloxan-induced diabetes was analyzed at two different time points using in situ hybridization. Some animals of each diabetic group were treated with insulin. Densitometric quantitation of silver clusters revealed that 5 weeks after diabetes induction P0 mRNA only is significantly increased, while at 14 weeks both P0 and MBP mRNA contents are markedly higher than controls. Insulin treatment normalizes glycemia levels and slightly counteracts increased P0 mRNA at both stages of diabetes. An increase in MBP mRNA is observed in chronic diabetic animals only, and is unaltered by the normoglycemic effect of insulin. The increased transcript levels of P0 and MBP suggest that Schwann cells can modulate gene expression of myelin-specific proteins in response to diabetic-induced metabolic derangement. Such a change may represent a higher turnover of myelin proteins as an attempt by the Schwann cells to repair the diabetes-induced nerve damage. The observed pattern of transcript amount is only slightly influenced by insulin treatment.

Animals↗

PubMed1996

Induction of p75NGFR in human diabetic neuropathy.

In this immunohistochemical study we investigated the expression of low-affinity NGF receptor (p75NGFR) in peripheral nerves from 16 patients with type I or type II diabetes mellitus. Fourteen nerves from age- and sex-matched normal individuals and nine nerves from non-diabetic patients with ischemic neuropathy served as controls. All nerve samples were preliminarily examined by standard histology, fiber teasing and electron microscopy. Increased p75NGFR immunoreactivity was detectable within the endoneurium of cross-sections from ischemic and particularly from diabetic nerves. Immuno-teasing demonstrated that p75NGFR immunostaining was distributed along the entire length of isolated nerve fibers undergoing axonal degeneration. Quantitative assessment of p75NGFR immunoreactivity, performed by histospectrophotometry and expressed as percentage of adsorbance, was 21.20 +/- 3.50 in nerves from diabetic patients, 13.35 +/- 3.62 in nerves from non-diabetic patients with ischemic neuropathy and 9.02 +/- 2.75 in normal controls. The increased expression of p75NGFR in diabetic nerves is consistent with an axonopathic defect and further suggests involvement of NGF and other neurotrophins in the pathogenesis of human diabetic neuropathy.

Adult↗

PubMed1996

L-carnitine and acetyl-L-carnitine in human nerves from normal and diabetic subjects.

Marked reduction in the contents of L-carnitine and acetyl-L-carnitine has been reported in peripheral nerves of rats with experimental diabetes. Since these substances have been claimed to improve a number of signs and symptoms of peripheral neuropathy in controlled clinical trials, this study was aimed at assessing whether nerves from diabetic subjects would also reveal similar decrease in the concentration of L-carnitine and acetyl-L-caritine. To this end, these substances were measured in nerves obtained from 11 patients with diabetic neuropathy, 13 patients with ischemic non-diabetic neuropathy, and 12 normal controls. Nerves from patients with either diabetic neuropathy and ischemic non-diabetic neuropathy showed levels of both carnitines lower than those from normal controls. However, differences among the three groups were not statistically significant, indicating that a reduction in these amino acids probably represents only a co-factor in the development of the variegated clinical picture of human diabetic neuropathy.

Acetylcarnitine↗

PubMed1995

Low-affinity nerve growth factor receptor expression in sciatic nerve during P2-peptide induced experimental allergic neuritis.

Northern blot, immunocytochemistry, and single nerve fiber immunostaining were used to determine the expression of low-affinity nerve growth factor (NGF) receptor (p75NGFR) in the peripheral nervous system of Lewis rats during the course of experimental allergic neuritis (EAN) induced with 100 micrograms of 'SP26' synthetic peptide, corresponding to residues 53-78 of bovine P2 myelin protein. This severe reversible polyneuropathy, characterized by extensive multifocal demyelination in nerve roots, and axonal degeneration within sciatic nerve, represents a useful tool to investigate Schwann cell gene expression in these different pathological conditions. Our results showed that both p75NGFR mRNA and protein were induced within sciatic nerve by day 18 and 23 after 'SP26' immunization. By this time, however, p75NGFR was not detectable in roots of cauda equina. These data demonstrate that, during EAN induced by immunization with 100 micrograms of 'SP26', p75NGFR is up-regulated in Schwann cells and in nerve fibers distally along the nerve. This suggests that the induction of the receptor in sciatic nerve during P2-peptide EAN is related to the loss of axonal contact by Schwann cells.

Animals↗

PubMed1994

Sulfatides trigger increase of cytosolic free calcium and enhanced expression of tumor necrosis factor-alpha and interleukin-8 mRNA in human neutrophils. Evidence for a role of L-selectin as a signaling molecule.

Sulfatides have been established recently as ligands for L-selectin, and we investigated whether they trigger transmembrane signals through ligation of L-selectin. We found that sulfatides trigger the increase of cytosolic free calcium in neutrophils and that this effect was strictly dependent on sulfation of the galactose ring, as non-sulfated galactocerebrosides were not stimulatory. Chymotrypsin and phorbol 12-myristate 13-acetate treatment of neutrophils caused shedding of L-selectin, but not of class I major histocompatibility complex antigens or beta 2 integrins, and blunted the capability of neutrophils to respond to sulfatides with an increase of cytosolic free calcium. Four different anti-L-selectin antibodies (DREG-200, LAM1/3, LAM1/6, and LAM1/10), but not four control antibodies directed against different surface molecules of neutrophils, also triggered an increase of cytosolic free calcium. The anti-L-selectin antibodies were stimulatory both if used in a soluble form, after cross-linking with anti-mouse F(ab')2 fragments, and immobilized to protein A of Staphylococcus aureus through the Fc fragment. With immobilized antibodies, an increase of cytosolic free calcium was found also by plating neutrophils on antibodies bound to protein A-coated coverslips and monitoring the increase of cytosolic free calcium by fluorescence microscopy. Both sulfatides and anti-L-selectin antibody effects were not inhibited by pertussis toxin, thus indicating that a pertussis toxin-sensitive GTP-binding protein was not involved in signal transduction. Sulfatides also triggered an increase of tumor necrosis factor-alpha and interleukin-8 mRNAs in neutrophils. Also to act as stimuli of cytokine mRNA expression, sulfatides required sulfation of the galactose ring, as non-sulfated galactocerebrosides were not stimulatory, and depended on expression of L-selectin, as shedding of this molecules induced by chymotrypsin blunted their effects. These findings suggest that L-selectin can transduce signals activating selective cell function.

Calcium↗

PubMed1994

Expression of the low-affinity NGF receptor during human muscle development, regeneration, and in tissue culture.

The expression of the low-affinity NGF receptor (LNGFR) during human muscle development, regeneration, and in tissue culture was analyzed using a murine monoclonal antibody to human LNGFR (MAb ME 20.4). Muscle cells from 12-22-week fetuses stained strongly for LNGFR. In adult normal muscle, only intramuscular nerve endings showed immunoreactivity with MAb ME 20.4, but no staining was detected in muscle fibers. In Duchenne muscular dystrophy, immunohistologically demonstrable LNGFR was present in regenerating muscle fibers. In these fibers, LNGFR gene expression was also demonstrated at the transcriptional level using in situ hybridization with riboprobes coding with human LNGFR. Cultures from human fetal and adult muscle were studied by double label indirect immunofluorescence microscopy with MAb ME 20.4 and antisera against human fetal myosin. Most myosin-positive cells, both at the myoblast and myotube stages, displayed surface LNGFR immunostaining. In cells from fetal muscle, LNGFR was detected during the first 2 weeks in vitro, whereas in cells from adult muscle the expression of LNGFR was observed for up to 7 weeks. These findings suggest a potential involvement of LNGFR in human muscle development and regeneration.

Culture Techniques↗

PubMed1994

Multiple sclerosis and mitochondrial myopathy: an unusual combination of diseases.

A woman with definite multiple sclerosis (MS) and mitochondrial myopathy is described. There were widespread white matter lesions on magnetic resonance imaging (MRI), cerebrospinal fluid (CSF) abnormalities and evoked response changes. Muscle biopsy showed ragged red fibres (RRFs) and cytochrome c oxidase (CoX) deficiency. Southern blot analysis revealed a large deletion of mitochondrial DNA (mtDNA). The patient may be affected by two unrelated diseases, MS and mitochondrial myopathy, but this combination has never previously been reported.

Biopsy↗

PubMed1994

The Italian Longitudinal Study on Aging (ILSA): design and methods.

The Italian Longitudinal Study on Aging (ILSA) is a population-based, longitudinal study of the health status of Italians aged 65-84 years. The main objectives of ILSA are the study of the prevalence and incidence rates of common chronic conditions in the older population, and the identification of their risk and protective factors. ILSA is also designed to assess age-associated physical and mental functional changes. A random sample of 5632 individuals, stratified by age and gender using the equal allocation strategy, was identified on the demographic lists of the registry office of eight municipalities: Genova, Segrate (Milano), Selvazzano-Rubano (Padova), Impruneta (Firenze), Fermo (Ascoli Piceno), Napoli, Casamassima (Bari), and Catania. An extensive investigation, including interviews, physical exams, and laboratory tests, was conducted at baseline to identify the presence of cardiovascular disease (ischemic heart disease, hypertension, congestive heart failure, arrhythmia, intermittent claudication), diabetes, impaired glucose tolerance, thyroid dysfunction, dementia, parkinsonism, stroke, and peripheral neuropathy, as well as assess physical and mental functional status. The baseline examination was carried out between March 1992 and June 1993; a second comprehensive examination will begin in March 1995. An interim hospital discharge data survey and a mortality survey are currently ongoing to assess the hospitalization rate and the cause-specific mortality rate in this study cohort.

Aged↗

PubMed1993

Decrease of nerve Na+,K(+)-ATPase activity in the pathogenesis of human diabetic neuropathy.

A decrease in Na+,K(+)-ATPase activity is claimed to play a central role in the pathogenesis of electrophysiological and morphological abnormalities that characterize the neuropathic complications in different animal models of diabetes mellitus. The peripheral nerves from 17 patients with either type I or type II diabetes mellitus were studied to assess the importance of changes in Na+,K(+)-ATPase activity in chronic human diabetic neuropathy. Sixteen nerves from age- and sex-matched normal individuals, and 12 nerves from non-diabetic neuropathic subjects undergoing vascular or orthopedic surgery served as negative and positive controls, respectively. All specimens were processed blind. Ouabain-sensitive ATPase activity was measured by a modified spectrophotometric coupled-enzyme assay. Standard histology, fiber teasing and electron microscopy were used to establish the normal or neuropathological patterns of surgical material. Morphometric analysis permitted calculation of fiber density in each nerve specimen and correlation of this figure with the relevant enzymatic activity. Na+,K(+)-ATPase activity was approximately 59% lower in nerves from diabetic patients than in normal controls (P < 0.01) and approximately 38% lower in nerves from non-diabetic patients with neuropathy (P < 0.01). Although nerves from both neuropathic conditions had significantly fewer fibers than those from normal individuals (diabetic -33%, and non-diabetic -22%), the decreases in Na+,K(+)-ATPase activity and fiber density were not correlated only in specimens from diabetic patients (r2 = 0.096; P = 0.22). Taken together with data from experimental animal models, these results suggest that the reduction in Na+,K(+)-ATPase activity in diabetic nerves is not an epiphenomenon secondary to fiber loss; rather, it may be an important factor in the pathogenesis and self-maintenance of human diabetic neuropathy.

Adult↗

PubMed1993

Myelin protein transcripts increase in experimental diabetic neuropathy.

A Northern blot analysis of P0 and MBP myelin protein transcripts in the sciatic nerve from rats with alloxan-induced diabetes at two different time points is described. After 5 weeks of diabetes induction, only P0 mRNA is significantly increased by 39%, while at 14 weeks both P0 and MBP mRNA contents are markedly higher than controls. Insulin treatment normalizes glycemia levels, partially counteracts P0 mRNA increase at both stages of diabetes and delays MBP mRNA increase present only in chronic animals. We suggest that increased transcript levels of P0 and MBP in Schwann cells may represent a higher turnover of myelin sheath specific proteins in diabetic syndrome, as attempt to repair the hyperglycemia-induced nerve damage, which is partially prevented by insulin treatment.

Animals↗

PubMed1993

Production of tumor necrosis factor and other proinflammatory cytokines by human mononuclear phagocytes stimulated with myelin P2 protein.

In this study we examined the effect of myelin P2 protein on some proinflammatory functions exerted by human mononuclear phagocytes. Northern blot analysis demonstrated that P2 protein selectively induced in monocytes and macrophages mRNA accumulation of tumor necrosis factor (TNF), interleukin 1 beta (IL-1 beta), and interleukin 8 (IL-8) in a time-dependent manner. Natural killer stimulating factor (IL-12) mRNA and protein secretion was strongly induced by lipopolysaccharide but not by P2 protein. Supernatants harvested from P2-stimulated monocytes contained significant amounts of TNF, IL-1 beta, and IL-8, whereas those from macrophages contained only TNF and IL-8. The effect of the P2 protein on TNF and IL-8 mRNA accumulation and secretion was not affected by polymyxin B, which, on the other hand, almost completely abolished the effect of lipopolysaccharide. Finally, P2 protein did not directly trigger hydrogen peroxide release but, through the induced release of TNF, potentiated monocyte respiratory burst capability. Since P2 protein is the antigen responsible for the induction of experimental allergic neuritis, these findings identify a potential mechanism involved in the inflammatory reaction and myelin damage during experimental allergic neuritis.

Cytokines↗

PubMed1993

Appearance of PLP mRNA in specific regions of the developing rat lumbosacral spinal cord as revealed by in situ hybridization.

The capacity of specific regions and fiber tracts of developing rat lumbosacral spinal cord to express proteolipid protein (PLP) mRNA was examined using in situ hybridization. PLP mRNA was undetectable at Day 18 postfertilization but present in the white matter by Postnatal Day 0 (P0). Initially, levels of PLP mRNA were higher in ventral than in dorsal funiculi. Hybridization signal was observed in the corticospinal tract by P10. Appearance of PLP message in gray matter lagged several days behind that in white matter. The expression of PLP mRNA in gray matter rose between P10 and P40 and the abundance of PLP transcript remained high in white matter during the same period. In the adult spinal cord some oligodendrocytes in the Lissauer tract and in the posterior commissure expressed low levels of PLP mRNA, which was undetectable in the substantia gelatinosa. Comparing the time of emergence of PLP mRNA to the histological appearance of myelination gave evidence that the message is expressed in oligodendrocytes that are not many days away from myelin formation. These results provide new information on the topographic distribution of PLP mRNA during myelination of the rat spinal cord.

Animals↗

PubMed1992

Sural nerve immunoreactivity for nerve growth factor receptor in a case of localized hypertrophic neuropathy.

Immunoreactivity for nerve growth factor receptor (NGFR) was examined using a monoclonal antibody against human NGFR in the sural nerve of a 24-year-old woman, affected by localized hypertrophic neuropathy (LHN). NGFR expression was correlated with electron microscopy and with immunoreactivity for S-100 protein, laminin, HLA-DR, HNK-1, P0 glycoprotein and neurofilament peptides. Our results indicate that in LHN most of whorl-forming cells are NGFR positive and S-100 protein or HLA-DR negative. These data along with the ultrastructural features suggest their origin from perineurium.

Adult↗