Biomedical subjects

S Beretta

Publications and source records attributed to S Beretta.

28 records · Page 2Linked to original sources

PubMed1997

Auditory event-related potentials in Parkinson's disease.

We studied 49 patients with Parkinson's disease (PD) by a neuropsychological battery examining the temporo-spatial orientation, short-term memory, comprehension, non-verbal intelligence, long-term memory and anomia and the Auditory Event-Related Potentials. In the patients the latencies of the N100 and N200 waves were prolonged and the amplitude of the P300 wave was reduced compared with controls. No difference was found in the ERP of patients with and without cognitive deficits. Equally, no correlation was found between the ERP, the cognitive impairment, the length or the severity of the disease evaluated by Hoehn-Yahr's and Webster's scales.

Aged↗

PubMed1993

Routine endometrial curettage is not indicated at the time of cervical cone biopsy.

Endometrial currettage is commonly performed after cervical cone biopsy to detect occult endometrial abnormalities. Recently, this practice has been questioned and specific criteria promulgated to reduce the number of concomitant endometrial curettages performed at the time of cone biopsy. To investigate the reliability of these criteria, we reviewed the records of 370 women who underwent cold-knife cervical cone biopsy, 323 (87.3 percent) of whom underwent concomitant endometrial curettage. Significant endometrial abnormalities were present in only 18 women, each of whom met at least one specific criterion for endometrial currettage. In contrast, 23 endometrial currettings either contained cervical tissue (five patients) or were insufficient for diagnosis (18 patients). The incidence of complications directly attributable to endometrial curettage was 1.6 percent. We conclude that limiting endometrial curettage at the time of cone biopsy to those women meeting specific criteria would significantly reduce the number of endometrial currettings performed, without hindering the ability to detect significant endometrial abnormalities. Such a reduction would minimize surgical morbidity and could save $13 million annually in the United States.

Adolescent↗

PubMed1992

High-dose intravenous human immunoglobulin in polymyositis resistant to treatment.

Two patients were treated with treatment-resistant polymyositis with intravenous immunoglobulin over four days at a dose of 0.4 g/kg/day. Clinical recovery followed within two months. Serum creatine kinase (CK) activity decreased to normal, and a clear improvement in muscle strength was observed. One patient showed neither clinical relapses nor increase in serum CK activity after 20 months. The other showed a mild increase in serum CK activity after 24 months and was successfully retreated with intravenous immunoglobulin. There were no significant adverse side effects.

Antiviral Agents↗

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↗

PubMed1990

Quantitative assessment of class II molecules in normal and pathological nerves. Immunocytochemical studies in vivo and in tissue culture.

We have analysed class II molecules (HLA-DR) expression in human fetal nerves at different stages of gestation, in human control nerves and in nerves of patients with peripheral neuropathies of different aetiology. Immunochemical demonstration of HLA-DR antigens was also performed on isolated human Schwann cells at different times in culture, from the same nerves. In normal nerves, HLA-DR positive material is localized only on endothelial and perivascular cells and in rare perineurial and endoneurial cells. In fetal nerves, HLA-DR positive material is already present by the sixteenth week of gestation. Quantitative analysis of HLA-DR molecules density in pathological nerves showed a wide heterogeneity in different neuropathies with no correlation between the type of pathology and the intensity and pattern of staining. Cultured human Schwann cells obtained from fetal, normal adult and pathological (vasculitic neuropathy) nerves were HLA-DR positive and the percentage of positive cells increased with time in culture. DR antigen appearance on human Schwann cells may reflect not only an immunologically-mediated phenomenon but also a dependence on axon-Schwann cell interaction.

Adult↗

PubMed1989

Rapid quantitative immunohistochemical assessment of human peripheral neuropathies using a monoclonal antibody against nerve growth factor receptor.

An analysis of nerve growth factor (NGF) receptor expression and density in human sural nerve biopsies was performed by immunocytochemistry with a murine monoclonal antibody against the human NGF receptor. Quantitative assessment of immunostaining density was made by histospectrophotometry on frozen sections. Although there was enhanced expression of NGF receptor within endoneurium in all patients with clinical neuropathies, expression was highest in nerves with axonal disease, consistent with the proposal that disruption of axon-Schwann cell interactions triggers the re-expression of the NGF receptor. These results with human nerves, together with previous studies with animal models, suggest that NGF and NGF receptor play important roles in the general response to neuronal injury.

Adult↗

PubMed1988

Cultures of human Schwann cells isolated from fetal nerves.

We describe a technique for the preparation of highly purified populations of Schwann cells (SC) from human fetal nerves. Cultures were prepared by chemical and mechanical dissociation of human fetal sciatic nerves by modification of the method of Kreider et al. developed for newborn rat nerve. A time course analysis of some SC-associated markers at different times in vitro was performed employing immunofluorescence (IF) and immunoperoxidase (IP) to determine the percentage of SC in culture and to evaluate the maintenance of specific SC characteristics. We compared this method with that of Askanas et al. which produces enriched SC cultures by utilizing successive re-explantation of the original nerve explant. After 48 h, approximately 90% of the cells were bipolar and S-100+ and over the next two weeks about 70-80% of cells were SC by cytologic and immunocytologic criteria. At 35 days, 35% were SC, whereas less than or equal to 2.5% of 35-day-old multi-explant cultures were SC. The SC obtained by this method displayed the typical morphological and immunological characteristics: they expressed surface laminin and nerve growth factor receptors, whereas fibronectin, which is localized on fibroblast surface, was absent.

Cell Separation↗

PubMed1987

Human Schwann cells: cytochemical, ultrastructural and immunological studies in vivo and in vitro.

Cytochemical, ultrastructural and immunological properties of human Schwann cells were studied in normal adult and foetal nerve sections and in tissue cultures. As specific markers for Schwann cells we used S-100 protein and laminin. The presence of Sudan black-positive, Oil Red-O-negative material was found in Schwann cells in vitro. Structural features, examined at E.M. level, are described. This information may be useful in nerve tissue culture studies, a new tool for the investigation of dyschwannian neuropathies.

Cells, Cultured↗

PubMed1986

S-100 protein and laminin: immunocytochemical markers for human Schwann cells in vitro.

Human fetal and adult Schwann cells, which had been maintained in culture for 5 weeks according to an explant-reexplantation technique, were labeled by immunoperoxidase using antibodies directed against S-100 protein and laminin in order to find specific antigenic markers. Immunocytochemical analysis of the distribution of both proteins showed that they were expressed in long-term cultures. The localization of S-100 protein and laminin in long-term cultures indicated that the expression of these proteins by human Schwann cells was not axon-dependent and also occurred in absence of myelin synthesis.

Cells, Cultured↗

PubMed1986

Analysis of fibronectin expression during human muscle differentiation.

Fibronectin expression during human muscle differentiation was investigated by determining its distribution in foetal, normal adult and dystrophic muscle and in foetal, normal adult and dystrophic muscle cultures during myogenesis. Muscle sections and muscle cultures were studied by indirect immunofluorescence staining using polyclonal and monoclonal anti-human antibodies. Mass and clonal muscle cultures were prepared from foetal, adult and dystrophic muscle tissue. Immunofluorescence staining detected fibronectin on the epimysium, perimysium and endomysium of transverse sections of normal adult muscle, while sarcoplasm was devoid of this glycoprotein. In foetal muscle, some fibers showed a prominent ring of fibronectin. In mass and clonal cultures, myoblasts were found to synthesize and accumulate fibronectin while myotubes did not. No difference in fibronectin distribution was observed between Duchenne Muscular Dystrophy (DMD) and control myotubes. An enzyme-linked immunoassay (ELISA), performed on homogenated muscle, sonicated fibroblasts and muscle cells, showed a high fibronectin level in fibroblasts when compared with the other samples tested.

Adult↗