PubMed Health⌕ Search

Biomedical subjects

S Scarpa

Publications and source records attributed to S Scarpa.

78 records · Page 5Linked to original sources
PubMedDate not supplied

Changes in fibronectin production in rat liver during cirrhotic evolution due to treatment with CCl4 and steroid hormones: correlation with plasmatic fibronectin.

Previous our studies showed that some steroid hormones, as pure crystalline Progesterone (pPc) and 17-alpha-hydroxyprogesterone capronate (17 alpha HPC) heightened the cirrhogenic action produced in rat liver by carbon tetrachloride. Medroxyprogesterone (MPA), however, did not appear to promote cirrhosis, but increased just steatosis. In the present paper, we have studied the above mentioned steroid hormones for their possible capability of inducing changes in plasma fibronectin concentration. For this purpose, the soluble plasma fibronectin level was measured in female rats 45 days after CCl4-induced cirrhosis, and it was compared with the insoluble fibronectin of liver (detected by immunostaining) and the collagen content in the organ. The results obtained show that, after treatment with CCl4 and MPA, both plasma and liver fibronectin content strongly increases, whereas liver collagen content lowers. However, after treatment with CCl4 alone or in association with the other two steroid hormones, any changes in fibronectin content is not observable, but, on the contrary, is evident a heightened collagen production associated with a cirrhotic change of liver.

17 alpha-Hydroxyprogesterone Caproate↗
PubMedDate not supplied

A novel 500,000 Da, linear, single chain extracellular protein synthesized by several childhood tumors.

A high molecular weight extracellular protein has been purified from cell culture medium of Ewing's sarcoma cell lines, by high performance liquid chromatography and electroelution from SDS-PAGE electrophoresis. This protein has an apparent molecular mass of about 500,000 Da on SDS-PAGE. Immunoprecipitation studies with several extracellular matrix glycoproteins (laminin, fibronectin) specific antisera indicate it is a separate protein. Reduction of disulphide bonds with 2-ME or DTT fails to significantly alter its migration on SDS-PAGE gels, other than a slight apparent increase in molecular mass, indicating an apparent single polypeptide chain structure. The slightly greater mobility observed in unreduced gels suggests one or more regions of intrachain disulfide bonding. It is sensitive to pepsin and trypsin, but resistant to bacterial collagenase indicating that it does not contain collagenous domains. Metabolic labelling with 3H-proline, 3H-leucine, and 35S-methionine indicate that this protein is proline-poor, but leucine, and especially methionine, rich. Sodium 35S-sulfate incorporation is totally negative and treatment with glycosaminoglycan degrading enzymes has no effect on the mobility of the protein on gels, unlike typical proteoglycans. This protein appears by rotary shadowing electron microscopy as a long, thin, filamentous molecule at least 500 nm (0.5 um) in length. The tissue localization and function are unknown at this time, but are under active investigation.

Child↗
PubMedDate not supplied

Ultrastructural and immunohistochemical characterization of the tunica albuginea in Peyronie's disease and veno-occlusive dysfunction.

The tunica albuginea and corpus cavernosum from patients with Peyronie's disease (PD), patients with veno-occlusive dysfunction (VOD), and those from normal control subjects were studied by transmission electron microscopy and immunohistochemical staining for type I, III, and V collagens, platelet-derived growth factor (PDGF) AA and BB homodimers, and PDGF alpha and beta receptors. Ultrastructural modifications resembling a fibrotic reaction were detected in the two pathological tunica albuginea, but not in those from control subjects. Ultrastructural data demonstrated a general increase in fibrous and amorphous extracellular matrix material in the pathological tunica albuginea. The amorphous material probably represents glycoproteins and proteoglycans. The fibrous material, representing collagen, appears disorganized in the tissue and does not display the typical and homogeneous diameter, size, and spatial arrangement. Large areas of extracellular and intracytoplasmic, partially degraded, fibers are visible. An increased type I/III collagen ratio was detected by immunohistochemistry in the two pathological tunica albuginea. Moreover, a strong expression of type V collagen, correlated to fibroblasts, was revealed. Fibroblasts from control tissues, on the other hand, were totally negative. Finally, PDGF AA and BB were positive in fibroblasts from pathological tunica albuginea but were negative in control tissues. PDGF beta receptor was positive in pathological and normal tissue fibroblasts. Tunica albuginea from PD and VOD show similar ultrastructural and immunohistochemical alterations, whereas the corpus cavemosum shows no visible modifications.

Collagen↗
PubMedDate not supplied

[Effects of PDGF AB on extracellular matrix synthesis by human mammary fibroblasts].

PDGF AB effect on extracellular matrix protein synthesis and release by a primary culture of non transformed human mammary fibroblasts was analyzed. Primarily PDGF AB induced a modified protein distribution, with a global enhancement of secreted proteins as compared to intracytoplasmatic proteins. Furthermore, an increase in synthesis and release of the extracellular matrix proteins such as fibronectin and type I and IV collagens upon PDGF AB treatment with specific immunoprecipitation was demonstrated.

Aged↗