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E Ruocco

Publications and source records attributed to E Ruocco.

30 records · Page 2Linked to original sources
PubMed1999

Pemphigus and pemphigoid-like effects of nifedipine on in vitro cultured normal human skin explants.

BACKGROUND: A variety of drugs have been implicated in the onset and exacerbation of pemphigus and bullous pemphigoid. The demonstration of biochemical acantholysis in skin explants to various drugs in the absence of autoantibodies, in which the tested drugs evoke a biochemical reaction that leads to desmosomal function loss, may be a valuable adjunct to patient management by confirming the suspicion of drug-related pemphigus or bullous pemphigoid. OBJECTIVE: To determine whether a skin explant model might serve as a possible in vitro correlate of drug-induced pemphigus and pemphigoid-like effects related to the calcium channel blocker nifedipine. METHODS: Normal human breast skin obtained from nonpemphigus and nonpemphigoid patients undergoing mastectomy was cultured with nifedipine at final concentrations of 2, 4, and 8 mM. The drug effect on skin explants evidenced by morphologic changes was evaluated by microscopy by three observers. RESULTS: Five out of seven explants cultured with nifedipine at concentrations ranging from 2 to 8 mM exhibited obvious morphologic changes of two types: intraepithelial (or pemphigus-type) splittings and subepithelial (or pemphigoid-type) splittings. Two explants showed no acantholysis and no subepithelial splittings. Control cultures without polyethylene glycol 200 (PEG) showed no changes. Skin control samples cultured in medium supplemented with 10% PEG displayed vacuolar degeneration throughout the entire epidermis, but no sign of cell-cell dyshesion or dermo-epidermal detachment. CONCLUSIONS: A type of skin susceptibility to nifedipine may be genetically determined, with some nifedipine-treated patients developing an acantholytic reaction and others a subepidermal bullous eruption.

Aged↗
PubMed1999

In vivo enalapril-induced acantholysis.

Enalapril is a widely used antihypertensive drug with a very powerful in vitro acantholytic effect. It has been known to potentially induce pemphigus in genetically predisposed subjects. The action mechanism is complex and still only partially understood. We describe the case of a 66-year-old man, affected with intermediary basal cell carcinoma, in whom the histological examination showed suprabasal acantholytic clefts in the perilesional epidermis. Surprisingly a second biopsy taken from the apparently healthy skin of his back confirmed the presence of acantholytic changes. Clinical signs of pemphigus were absent. The patient's history did not reveal any relevant data but a mild arterial hypertension that had been treated for 1 year with 10 mg enalapril. Taking into account the patient's history (enalapril long-term administration), the absence of any bullous or erosive lesions and the histological findings, a diagnosis was made of in vivo enalapril-induced acantholysis.

Acantholysis↗
PubMed1998

Lipoteichoic acid and protein-A from Staphylococcus aureus stimulate release of hepatocyte growth factor (HGF) by human dermal fibroblasts.

In this study we demonstrated that Staphylococcus aureus lipoteichoic acid (LTA) and protein-A (PA) induce the release from human dermal fibroblasts of hepatocyte growth factor (HGF), a proliferation factor of epithelial cells (including keratinocytes). In contrast, LPS and porins from Pseudomonas aeruginosa did not stimulate HGF production. Recombinant human IL-1 beta induced HGF release. This production was synergistically enhanced when in association with LTA (by more than twice) and PA (by about two-thirds). Controls were performed in the presence of bacterial components alone. In previous studies we have shown that LPS and porins are inducers of IL-1 alpha and beta and other cytokines from human monocytes. Therefore it is possible that in inflammatory cutaneous foci and infected wounds, bacterial components may induce HGF release from dermal human fibroblasts. LTA and PA act directly, while LPS and porins act indirectly, through the release of cytokines by monocytes/macrophages. HGF plays an important role in the repair of cutaneous tissue during gram-positive and gram-negative infections.

Adult↗
PubMed1998

Different patterns of in vitro acantholysis in normal human skin samples explanted from different sites of the body.

BACKGROUND: The factors that contribute to a preferential anatomic localization of pemphigus lesions are not well known. In particular, the question arises as to whether certain skin areas may be more acantholysis-prone than others. OBJECTIVE: To verify whether, in pemphigus patients, a different susceptibility to acantholysis exists among different cutaneous regions, the technique of tissue cultures was used. METHODS: Normal human skin explants from two distinct anatomic regions (back and buttocks) of two former pemphigus patients were cultured in vitro in the presence of enalapril (6 mM) or cystamine (10 mM), two substances with a proven biochemical acantholytic effect. After 4 days of culture, the tissues were processed for standard histology. RESULTS: Diffuse acantholysis, with large intraepidermal splits, was observed in the explants taken from the backs of both subjects and cultured with either enalapril or cystamine. Mild to moderate acantholytic changes were detected in the explants taken from the buttocks of both subjects and cultured with either enalapril or cystamine. No structural changes were seen in the control cultures. CONCLUSIONS: Pemphigus patients present different thresholds of acantholysis in different areas of their bodies. This might explain, at least in part, certain preferential anatomic localizations of pemphigus lesions.

Acantholysis↗
PubMed1997

Porins of Pseudomonas aeruginosa induce release of tumor necrosis factor alpha and interleukin-6 by human leukocytes.

The aim of this study was to examine the ability of Pseudomonas aeruginosa components to induce release of cytokines from human leukocytes. Human whole-blood cultures were incubated with several concentrations of purified P. aeruginosa products, including porins, exomucopolysaccharide, lipopolysaccharide, and toxin A. Supernatants were assayed for tumor necrosis factor alpha (TNF-alpha) and interleukin-6 (IL-6) activities. All of the P. aeruginosa components except toxin A were able to stimulate the release of both cytokines. On a weight basis, porins were as effective as lipopolysaccharide and significantly more effective than exomucopolysaccharide in inducing IL-6 release (P < 0.05). Moreover, porins were more potent than either exomucopolysaccharide or lipopolysaccharide in inducing TNF-alpha release (P < 0.05). Further experiments using isolated leukocytes suggested that monocytes were the cell population predominantly responsible for the production of both cytokines. These data indicate that P. aeruginosa porins are able to induce significant cytokine production. These components may be responsible for the chronically overactive inflammatory response associated with persistent lung infection in cystic fibrosis patients.

B-Lymphocytes↗
PubMed1989

Preparation and properties of gel-peptide immunoadsorbents.

The chemical complexity of peptides limits the choice of coupling procedures which can be used in the preparation of gel-peptide conjugates. Several immunoadsorbents have been investigated, in order to select those that permit the isolation of antipeptide antibodies in the highest yield and with optimal specific activity.

Amino Acids↗
PubMedDate not supplied

Specificity of anti-MHC class II antibody binding to synthetic peptides.

This study indicates that antibodies raised against a DR4,w6; DQw1,3 positive cell line may bind to synthetic peptides selected from the polymorphic amino acid sequences 51-59 and 63-79 on the DQw2 beta chain. This cross-reaction may be explained by the relatively high sequence homology of these sequences in the beta chains of class II histocompatibility antigens, and suggests that antibody binding to small peptides may be scarsely selective. Based on the observations of the reactivity of the antibodies with several cell lines, and comparison of the amino acid sequences of beta chains of DR and DQ molecules, an attempt to identify the cross-reacting epitope is presented.

Amino Acid Sequence↗