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T Lombardi

Publications and source records attributed to T Lombardi.

At least 55 records · Page 3Linked to original sources
PubMed1993

Distribution of neural and neural-crest-related antigens in human dental pulp by immunohistochemistry.

Human teeth (formalin-fixed, demineralized and paraffin-embedded as well as frozen sections of human dental pulp) were examined by immunohistochemistry to detect the presence and distribution of a series of neural and neural-crest-associated antigens: S-100 protein, neuron-specific enolase (NSE), glial fibrillary acid protein (GFAP), myelin basic protein (MBP) and neurofilaments (NF). Although several experimental pieces of evidence support a neural crest derivation for dental papilla and odontoblasts with the histological method used in the present study, these structures were immunonegative for most of the markers employed in the present investigation. Indeed, mesenchymal cells as fibroblasts and endothelial cells were devoid of immunostaining. Schwann cells were strongly immunostained by S-100, NSE and GFAP. Nerve fibres running in the pulp showed a positive labelling for NF, S-100 and MBP antisera. It is concluded that the lack of labelling of pulp cells (excepting nerves) by the neural and neural-crest-associated antibodies could be due to a loss of capacity to express these antigens during differentiation. However, the possibility that these antigenic determinants are expressed but outside the limits of sensitivity of immunohistochemistry cannot be ruled out. Further studies, including molecular biology techniques, are required to clarify these alternatives.

Adolescent↗
PubMed1993

Fusion of permanent mandibular molars associated with periodontitis: a case report.

Dental twinning derives from abnormal events during the embryological development of tooth germs. The majority of fused teeth are found in the deciduous dentition, particularly in the anterior region of dental arches. Fusion of posterior teeth is considered a rare event. We report here a true case of posterior fusion between a second and third mandibular molar occurring in a black African woman. The morphology and the position of this abnormal tooth were responsible for a related periodontal problem.

Adult↗
PubMed1993

Treatment of denture-induced stomatitis: a review.

Denture-induced stomatitis is the term used in the literature to indicate an inflammatory state of the denture-bearing mucosa. A large number of denture-wearing patients are affected by this lesion, particularly elderly people. Denture stomatitis is a multifactorial disease precipitated by several predisposing and aetiological factors. A number of different regimens are currently employed in treatment of this lesion. The management of denture stomatitis, with particular reference to recent findings, is reviewed. Mechanical plaque control and appropriate denture-wearing habits are the most important measures in prevention and treatment of the disease.

Anti-Infective Agents↗
PubMed1993

Foliate papillitis occurring in a child: a case report.

Foliate papillae may occasionally become irritated, resulting in an hypertrophy of lymphoid tissue. This condition has been described in the literature as foliate papillitis and has been reported to occur in adults. We describe here an unusual case of foliate papillitis in a 9-year-old girl. Clinically the patient presented a pronounced enlargement of one foliate papilla. Furthermore, the lesion had a polypoid morphology and the mass appeared microscopically as aggregates of lymphoid tissue showing a reactive hyperplasia.

Child↗
PubMed1993

S-100 protein in normal and pathologic oral tissues. A review.

S-100 protein is an acidic calcium binding protein widely distributed in different tissues and cells of different origin. The precise biological role of S-100 is still unknown, but several features suggest a function activity for this protein. Oral tissues have not been extensively studied for S-100 protein presence. Here, we review the investigations of S-100 protein content in normal oral tissues and oral pathological lesions. The immunolocalization of this protein is used to demonstrate evidence of neuroectodermal histogenesis and is useful in the differential diagnosis of certain neoplasms or proliferative conditions.

Gingiva↗
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

Expression of intermediate filaments and actins in human dental pulp and embryonic dental papilla.

The localization of different cytoskeletal proteins (keratin, vimentin, desmin, actin, and alpha-smooth muscle actin) was examined by immunohistochemistry in normal human adult dental pulp and compared with dental papilla of tooth germs. Keratin and actin were localized in enamel organ. Vimentin and actin were observed in the dental papilla and in the adult dental pulp. Desmin and alpha-smooth muscle actin were present only in the vessel walls. These data are discussed paying particular attention to the origin and the peculiar functional characters of the dental papilla and pulp.

Actins↗
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

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

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

The connective tissue cells of human dental pulp: an histologic and immunohistochemical study.

Twenty human healthy teeth were extracted for orthodontic purposes and processed for histological, and immunohistochemical examination. Odontoblasts were pseudostratified in depth of 1-8 cells in pulpward direction showing the zone of Weil and the cell-rich zone in coronal third pulp. In the central part of pulp tissue, fibroblasts were arranged as a network. These cells strongly immunoreacted with an antibody (monoclonal and polyclonal) directed against the intermediate filament vimentin. The product reaction was specifically located in the cytoplasm. Near vessels occasional lymphocytes and mast cells were also present. Collagen fibers formed a plexus below the cell-rich zone in middle and coronal pulp.

Connective Tissue↗
PubMed1990

Bowes human melanoma cell line. An immunocytochemical study.

Bowes human melanoma cell line was investigated immunocytochemically to localize S-100 protein, HMB-45 and intermediate filament proteins. The majority of the cells showed strong positive staining with antibodies directed against S-100 protein, HMB-45 and vimentin filaments. Antibodies directed against the other cytoskeletal proteins failed to show any reactivity. These findings suggest that this transformed cell line does not dedifferentiate in culture and continues to express the specific antigens of human melanoma cells. Thus, Bowes cell line provides a useful model for studying the cellular biology and pathology of malignant melanoma.

Humans↗
PubMed1989

S-100 protein localization in human adult dental pulp.

The pulp of third molar teeth was examined by immunofluorescence and immunoperoxidase using a specific antibody to detect S-100 protein-labelled cells. There was a strong positive reaction in macrophages and in Schwann cells ensheathing axons. The other cells within the pulp were negative.

Adult↗
PubMed1988

Immunohistochemical staining for vimentin filaments and S-100 protein in myxoma of the jaws.

Two jaw myxomas have been analyzed by a panel of antibodies to characterize this tumour type. Vimentin, but not keratin, neuron-specific enolase (NSE), glial fibrillary acidic protein (GFAP), neurofilament (NF), desmin and Factor VIII-related antigen (FVIII-AG), demonstrated positivity in the cytoplasm of the neoplastic cells. Moreover, an antibody against S-100 protein also showed a strong positive reaction in the cytoplasm of the tumour cells examined. Thus directly indicating a mesenchymal derivation for odontogenic myxoma, and is the first demonstration of S-100 protein within the cells of this tumour type.

Adult↗