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Biomedical subjects

D Cocchia

Publications and source records attributed to D Cocchia.

11 recordsLinked to original sources

Immunocompetent cell markers in human fetal astrocytes and neurons in culture.

During the past few years, evidence has accumulated that interaction with peripheral immune cells as well as immunoregulatory functions in the central nervous system (CNS) can be played by several types of brain resident cells. Since very little information is available in man, however, we investigated the presence of markers so far considered typical of immunocompetent cells in in vitro cultures of human fetal brain. Immunocytochemistry at the light, scanning, and transmission electron microscopic levels revealed positivity for a very restricted range of macrophage antigens in astrocytes, which, however, were incapable of phagocytosis. In particular, expression of the major histocompatibility complex-class II antigen HLA-DR was observed in the cytoplasm and on the cell surface of GFA-P+ astrocytes and increased with time in culture and cell passages. Among the T-lymphocyte markers tested, Thy.1 and CD4 were positive. Both neurons and astrocytes carried Thy.1 from early cell passages. Noteworthy was the presence of CD4, which serves as the receptor for AIDS virus, in neurons from the first 2 weeks, whereas astrocytes became positive after only 4-6 weeks. Even if most staining was in the cytoplasm, some was exposed on cell surface. Astrocytes were found positive for the B-lymphocyte marker CD21, the cellular receptor for Epstein-Barr virus, whereas CD24 was detected in both neurons and astrocytes. Both antigens are related to B-cell proliferation. Results are in favour of the hypothesis of human brain cells being actively involved in CNS immunological events.

Astrocytes

Correlation between P19 presence and MHC class II expression in human fetal astroglial cells cocultured with HTLV-I donor cells.

The possibility of a direct infection of human brain by HTLV-I, has been studied using an in vitro model. Human fetal astroglial cells were cocultivated with irradiated HTLV-I donor cell line MT-2, and assayed for the presence of HTLV-I core protein p19 after 1 week. Fifty-six per cent of GFAP positive astrocytes showed the viral core protein p19 and increased expression of Class II MHC antigens. Electron microscopy of astroglial cells exposed to HTLV-I revealed the presence of vacuoli-like structures containing viral core protein p19. Cell intermediate filament cytoskeleton was also disorganized. Even if this study does not provide direct evidence for virus replication inside astroglial cells, all these findings suggest that HTLV-I can indeed enter the cell and exert a cytopathic effect. Therefore the results of the present study are consistent with the hypothesis that astroglial cells could be involved in demyelination processes occurring in the HTLV-I associated neurological disorders, such as human associated myelopathy and tropical spastic paraparesis.

Astrocytes

Immunochemical and immunohistochemical detection of S-100-like immunoreactivity in spinach tissues.

S-100 proteins represent a group of closely related acidic, calcium binding proteins originally isolated from the mammalian nervous system and later detected in non-neural cell types and in a wide variety of vertebrate and invertebrate species. The present study used immunochemical and immunohistochemical methods to extend the investigation of S-100 during phylogenesis to plant tissues. The presence of S-100-like immunoreactive material was detected in extracts of spinach (Spinacia oleracea L.) terminal buds and young leaves by the ELISA method and by Western blotting using different anti-S-100 rabbit antisera. Using the PAP method, serial sections of young spinach leaves treated with the same antisera exhibited an immunoreaction product that was confined to the cytoplasm and nucleus (but absent from the vacuoles) in meristematic, epidermal, and parenchymal cells. The present data enlarge the field of investigation of S-100 proteins in the search of the function(s) of S-100 in biological organisms.

Animals

Immunohistochemical study of neuropeptide Y-containing nerve fibers in the human clitoris and penis.

The occurrence and distribution of neuropeptide Y in the human clitoris and penis was investigated by light immunohistochemistry. Neuropeptide Y-containing nerve fibers were detected in the tunicae of arteries and veins as well as among trabecular smooth muscle. The distribution pattern of the peptide was similar in both organs although a higher density of immunoreactive nerve fibers was detected in the penis. The immunolocalization of neuropeptide Y was also compared with that of neuron-specific enolase, a neuronal marker which labels the entire nerve network. It is suggested that neuropeptide Y is involved in the physiology of the penis and the clitoris, affecting vascular and nonvascular smooth muscle activity.

Adolescent

Satellite cells in developing spinal ganglia. An immunohistochemical study.

The present immunohistochemical study investigates the presence and distribution of S-100-containing glial cells in the early stages of development in human spinal ganglia. From the earliest ages investigated immunoreactive cells could be detected in a continuous layer at the periphery as well as inside ganglionic rudiments in close relationship with neural elements, both at the light and ultrastructural levels. The possibility that these glial cells, exhibiting such a distinctive distribution, play a modulatory role on microenvironmental influences during maturation could be taken into account. Neither glial fibrillary acidic protein nor myelin basic protein could be detected at the ages investigated.

Embryonic and Fetal Development

Satellite cells in the normal human adrenal gland and in pheochromocytomas. An immunohistochemical study.

In light of the recent finding of the S-100 antigen in satellite cells of the rat adrenal medulla, we looked for S-100-labelled cells in both the normal human adrenal medulla and in pheochromocytomas. Immunostaining enabled us to detect S-100-labelled satellite cells by both light and electron microscopy in a significant number of pheochromocytomas and, as expected, in the normal human adrenal medulla.

Adrenal Gland Neoplasms

Skin storage in liquid nitrogen. An ultrastructural investigation.

The problem of cell survival as well as the biochemical and histological effects on skin of low temperature storage in liquid nitrogen has already received attention. However, little is known of the submicroscopic alterations induced by such treatment. Our study shows that rapid or slow freezing, direct or mediate contact with the liquid nitrogen, pretreatment before freezing, type and concentration of cryoprotectants, all have various effects on the fine morphology of epidermal cells. Glycerol is shown as having better cryoprotective activity than DMSO at concentrations of 15% or less. Our data are examined taking into account all available reports on the problem of cryopreservation and the use of cryoprotectants.

Dimethyl Sulfoxide

Dermal vessels in acrodermatitis chronica atrophicans.

An ultrastructural investigation of two patients suffering from acrodermatitis chronica atrophicans revealed in the small dermal vessels swelling of the endothelial cells, material of probably plasmatic origin accumulated in the subendothelial area, and sleeves of basement membrane-like material on a concentric perivascular layout.

Acrodermatitis

[Passive post].

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Cementation