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Biomedical subjects

R Di Felice

Publications and source records attributed to R Di Felice.

14 recordsLinked to original sources
PubMed1992

Human odontoblasts contain S-100 protein-like immunoreactivity.

S-100 protein is a group of three closely related isoforms (S-100ao, S-100a, and S-100b). This protein was first described as unique to the nervous system but it has also been identified subsequently in a variety of cell types of neuroectodermal (i.e., melanocytes, glial cells) and non-neuroectodermal origin (i.e., Langerhans cells, adipocytes, chondrocytes). In the present investigation the presence of S-100 protein was studied in human odontoblasts using a specific polyclonal antibody directed against S-100 protein in immunoperoxidase labelling experiments. The S-100 protein was detected in the cytoplasm of odontoblasts. This result suggests that S-100 protein can play a role in odontoblast functions.

Antibodies↗
PubMed1992

Comparative immunohistochemical analysis between jaw myxoma and mesenchymal cells of tooth germ.

The histogenesis of jaw myxoma is still debated. According to some authors it arises from the primitive mesenchymal components of developing teeth. In this study, we have studied the expression of S-100 protein and vimentin in dental follicle, dental papilla and periodontal ligament cells using monoclonal and polyclonal antibodies. Myxoma of the jaw expresses vimentin and S-100 protein. On the contrary, as compared to jaw myxoma, the normal developmental structures were immunonegative for S-100 protein but stained for vimentin. These results could indicate a difference in the derivation other than tooth mesenchyma.

Biomarkers, Tumor↗
PubMed1991

[Lichen planus. Clinical diagnosis, epidemiology and pathogenesis].

Lichen planus is a common mucocutaneous disease of unknown etiology which was initially described a century ago. The specific etiology remains unclear. A number of relationships between lichen planus and other conditions have been noted. The lesions occur most commonly on the buccal mucosa. Gingival involvement occurs in approximately 10% of reported cases. The appearance of lichen planus is extremely variable which leads to confusion with other clinically similar disease entities.

Adult↗
PubMed1991

In vitro release of elastase from human blood and gingival crevicular neutrophils.

Peripheral PMNs were collected from blood, and crevicular PMNs separated by filtration from gingival washings in 13 patients, aged 22-75 y, who had varying degrees of gingivitis and periodontitis. After pre-incubation with cytochalasin B, the same number of crevicular and peripheral cells were incubated either in PBS (with Ca2+ and Mg2+) (spontaneous release) or in the same buffer containing increasing concentrations of FMLP (stimulated release); elastase activity was measured in the supernatant by a fluorometric technique. There was a higher spontaneous release of enzyme from crevicular than from peripheral neutrophils. The average elastase activity in the supernatant of 1 x 10(4) crevicular cells was more than five times higher than that obtained from the same number of peripheral cells. However, stimulated crevicular PMNs liberated smaller amounts of enzyme than did stimulated peripheral PMNs. These results suggest that crevicular PMNs are already releasing elastase, and are consistent with the possibility that lysosomal enzymes contribute to tissue damage during gingivitis and periodontitis.

Adult↗
PubMed1991

Felodipine-induced gingival hyperplasia: a clinical and histologic study.

This paper reports, for the first time, gingival hyperplasia in a patient treated with felodipine, a drug which belongs to the group of calcium ion antagonists. The observed gingival overgrowth was most significant in the area of interdental papillae of the anterior region of the mouth. The described hyperplastic tissue was characterized by a firm and pale appearance, with a normally stippled pattern. Histopathologically, a conspicuous increase of fibrous connective tissue, as well as an inflammatory infiltrate and hyperplasia of the overlying epithelium were observed. Consequently, the present observation adds another drug to the list of substances capable to induce gingival hyperplasia.

Adult↗
PubMed1991

[Focal epithelial hyperplasia].

Five cases of "focal epithelial hyperplasia" (FEH) of the oral mucosa observed in Switzerland are reported. The patients were of Turkish and North African extraction. The lesions of FEH were multiple, painless, located at various sites of the oral mucosa including the tongue in the form of either soft papules or hard nodules. Evidence of a human papilloma virus origin was ascertained. Among the 1067 cases reported in the literature and reviewed for this study, this condition has been described to occur among American Indians, Eskimos and North African, also in Israeli and European cases the disorder was often reported in individuals of Turkish or North African extraction.

Adult↗
PubMed1991

Analysis of pH variation of various calcium hydroxide compounds in vitro.

Among the reasons for the use of calcium hydroxide products, there is their alkalinity. Variations in the alkalinity of six commonly used calcium hydroxide compounds were studied in vitro at different time intervals. All these compounds rendered the saline solution strongly alkaline. Dycal, Life, Nucap and Reocap, had a weaker effect as compared with Contrasil and to Pulpdent paste. Such differences in the pH values were accompanied by differences in calcium loss, as revealed by scanning electron microscopy. Differences in the alkaline pH values and calcium losses among these calcium hydroxide compounds may account for their different clinical effectiveness in vivo.

Calcium Hydroxide↗
PubMed1991

[Myxoma of the jaws].

A review of the literature and two observations made by the Authors regarding maxillary myxoma allow a closer analysis to be made of this rare benign tumour which is, however, often recurrent in young adults. Maxillary myxoma is identified by the appearance of a non-inflammatory and often painless swelling which, in radiological terms, appears to have a zone of multilocular and sometimes unilocular osteolysis. In histological terms, this globular whitish-greyish gelatine-like tumour is made up of an abundant stroma which encloses star-shaped or fusiform cells and rare collagen fibres. Treatment should be conservative where possible since radical surgery does not preclude recurrence; follow-up should be regular and long in order to ensure an early diagnosis of recividation. Although it is considered an odontogenic tumour, the odontogenic nature of maxillary myxoma has not been undisputably ascertained. The term maxillary myxoma is therefore preferable to that of odontogenic myxoma.

Adult↗
PubMed1990

Synthesis of alpha 2-macroglobulin in human gingiva: a study of the concentration of macroglobulin and albumin in gingival fluid and serum.

Albumin and alpha 2-macroglobulin were analysed in gingival fluid collected by filter paper strips from 6 volunteers before, during and after 10 days of dental plaque accumulation. The two proteins were also determined in samples of venous blood at the beginning of abstention from tooth brushing and 10 days later. A nephelometric technique was used for the analysis of albumin, but alpha 2-macroglobulin was determined by ELISA. The plaque and gingival indices, as well as the flow of gingival fluid, increased significantly during the period of plaque accumulation and then returned to baseline values. The concentrations of the two proteins in blood remained within normal limits. In gingival fluid, however, the concentration of albumin increased about two-fold at the peak of inflammation, while that of alpha 2-macroglobulin increased as much as 6 times. The enhanced passage of alpha 2-macroglobulin into the gingival sulcus in comparison to the entirely plasma-derived albumin was consistent with the concept that the greater excretion of globulin during inflammation must be due to an increased local synthesis.

Adult↗
PubMed1990

[Amalgam fillings and T-lymphocyte changes].

Dental amalgam and nickel alloys have been considered quite safe. Previous authors reported the effect of dental amalgam and nickel alloys on human T-lymphocytes modifications after amalgam dental fillings, into dose-dependence of any modifications and into possible temporary. Eight patients were subjected to dental care with amalgam dental fillings. Drawings of blood were executed at start, fifteen days after late fillings and two months later. The results about modifications of T-lymphocytes were not univocal. We believe, at now, that temporary modifications of the immunity seem to be related to a cytotoxic mechanism.

Adolescent↗
PubMed1990

[Intramandibular inclusions of salivary gland tissue].

Salivary gland tissue inclusions in the mandible appear as well delimited radiolucency areas, asymptomatic, usually located in the mandibular angle and sometimes in the premolar canine and symphysis regions. The examination of 8,500 radiographs has demonstrated an incidence of one radiolucent area at the mandibular angle every 500 radiographs. Our result is slightly inferior to the mean reported in the literature. Seven cases were examined. Six of them have been treated surgically and histologically. At exploration a defect in the lingual cortical plate was found. The cavities were filled by salivary gland tissue. The contents of the cavities were attached via the lingual cortical defect to the near salivary gland. The cause of such radiolucency situated in the mandibular angle seems to be an altered resorption and apposition process of the bone triggered by a modification of the salivary glands elasticity; on the contrary, the salivary inclusions in the symphysis region is referred to as embryonic origin. In the literature different terms are used often in relation with a pathogenetical hypothesis; in this paper we suggest rather a description terminology such as intramandibular salivary tissue.

Adult↗
PubMedDate not supplied

[Psychogenic oral paresthesia].

Psychogenic oral paresthesia represent a proteiform condition, more and more frequent. The failure to recognize it can lead to unjustified investigations or/and procedures. These manifestations are secondary to a psychic problem which varies in severity. In most cases, the establishment of a trust relationship, explanations to the patient and eventually a psychotherapy are sufficient to eliminate the symptoms. In severe cases, a psychotherapy or a psychiatric treatment are almost always necessary.

Adult↗