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Biomedical subjects

E Scarpini

Publications and source records attributed to E Scarpini.

At least 19 recordsLinked to original sources
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↗
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↗
PubMed1992

Congenital myopathy with type 2A muscle fiber uniformity and smallness.

We describe a 12-year-old girl with congenital myopathy. ATPase histochemical reactions and immunocytochemical analysis of muscle fiber-type composition with monoclonal antibodies against slow, fast (2A and 2B) and fetal myosin demonstrate that this congenital disease is characterized by type 2A muscle fiber uniformity and smallness. This is an unusual feature for a congenital myopathy in which the fiber type predominance, when present, is confined to type I.

Biopsy↗
PubMed1992

Oxiracetam in dementia: a double-blind, placebo-controlled study.

A multicentre, double-blind, between-patient study was carried out to evaluate the efficacy and tolerability of oxiracetam (800 mg tablet), in comparison with placebo, each given twice daily for 12 weeks to patients suffering from primary degenerative, multi-infarct or mixed dementia. Efficacy was assessed by a neuropsychological battery (simple reaction time, controlled associations, short story, Raven's Progressive Matrices, token test, digit span, word list learning), administered at the beginning and at the end of the study, and by a quality of life scale, administered at entry and after 6 and 12 weeks treatment. Sixty-five patients (28 men, 37 women, mean age 71 yrs) were enrolled; 58 completed the study: 2 on oxiracetam were withdrawn because of poor tolerability, 2 (one in each group) were withdrawn for poor compliance, one (on oxiracetam) for the occurrence of a transient ischaemic attack (defined as not related to the treatment) and 2 for administrative reasons. A significantly (p < 0.01) different effect in favour of oxiracetam was observed on the quality of life scale, and confirmed by significant (defined according to the Bonferroni technique) differences in some neuropsychological tests (e.g. controlled associations, short story). Four patients in the oxiracetam group complained of a total of 5 unwanted effects, and 1 on placebo complained of 3 unwanted effects, but none of them was withdrawn from the study.

Aged↗
PubMed1992

Phenotypic and proliferative properties of Schwann cells from nerves of diabetic patients.

The phenotypic (morphologic and antigenic) properties and mitotic index of cultured Schwann cells obtained by dissecting nerves from six diabetic patients were studied. These features were compared with those of Schwann cells cultured in vitro from six normal control nerves. Preservation of the specific antigenic properties of cells, identified with rabbit antiserum as bovine protein S-100, was documented by immunofluorescence with monoclonal antibodies against laminin, fibronectin, histocompatibility antigens HLA-A, B, C and -DR, HNK-1 antigen and the human receptor for nerve growth factor. The cell proliferation index was assessed by incorporation of bromodeoxyuridine. The results of the study showed that the mitotic capacities of Schwann cells from diabetic nerves cultured in vitro remained comparable with those of normal control cells. As regards phenotypic characteristics, no modifications were detectable by immunofluorescence. These findings suggest that the phenomena of demyelination and remyelination, sometimes with onion bulb features, which can be observed in some cases of diabetic neuropathy, are not due to a primary dysfunction of the Schwann cells but are secondary to axonal degeneration.

Adult↗
PubMed1991

Appearance and localization of dystrophin in normal human fetal muscle.

We studied the localization of dystrophin in normal human fetal muscle by immunohistochemistry. Our results show the appearance of dystrophin at week 11 and a progressive organization of the protein along membrane in the following weeks of gestation. At week 22 almost all fibers show a clear membrane immunostaining. Concomitant analysis of muscle fiber-type composition reveals no correlation between progressive appearance of dystrophin and muscle fiber-type differentiation. Our findings suggest that synthesis and localization of dystrophin in developing human skeletal muscle is time-related and probably independent of neuronal influences.

Dystrophin↗
PubMed1991

Lysosomotropic agents induce morphological and functional changes in human muscle cells in vitro.

We studied the distribution of lysosomes in differentiating human muscle cells in culture treated with propranolol, leupeptin and chloroquine. Chloroquine treated cells showed a significant vacuolization and an increase of the lysosomal apparatus as assessed by cytochemical analysis of the lysosomal enzyme acid phosphatase and by acridine orange staining. At electron microscopic level, an increase of lysosome-like bodies and disorganization of the contractile apparatus were demonstrated in multinucleated myotubes. These alterations observed in cultured muscle cells suggest that lysosomotropic agents may be harmful.

Cells, Cultured↗
PubMed1990

The ontogenesis of Fc gamma receptors and complement receptors CR1 in human peripheral nerve.

The ontogenesis of Fc gamma receptors (FcR) and C3b/C4b receptors (CR1) was studied in peripheral nerves from ten fetuses aged from 20 to 38 weeks using immunohistochemical and functional assays. Monoclonal antibodies (mAbs) against FcR and CR1 stained nerve fibers at 10 weeks of gestation and the staining intensity increased during nerve maturation. FcR and CR1 are probably expressed on Schwann cells and are early markers during the development of peripheral nerves. Functional FcR activity was detected in nerve sections before initiation of myelination, which occurs at approximately 18-19 weeks, whereas functional CR1 activity was found in the sections after myelination. Functional CR1 activity may, therefore, be related to myelin. The ontogenesis of FcR and CR1 was also studied on Schwann cells in culture from three fetuses aged 14, 16 and 19 weeks, using immunofluorescence technique with mAbs. The FcR and CR1 are lost on cultured Schwann cells. This suggests that the receptors are not intrinsic to the cells or that Schwann cells require axonal contact for the expression of FcR and CR1.

Antibodies, Monoclonal↗