PubMed Health⌕ Search

Biomedical subjects

R A Monteil

Publications and source records attributed to R A Monteil.

At least 19 recordsLinked to original sources
PubMed1992

Epstein-Barr virus DNA detection in gingival tissues of patients undergoing surgical extractions.

The main oral manifestation of Epstein-Barr virus (EBV) infection is hairy leukoplakia, a lesion associated with the acquired immunodeficiency syndrome (AIDS) and occasionally in other immunocompromised patients. However, the recent literature describes the presence of viral genome in clinically normal oral tissues. The purpose of this work was to investigate these occult EBV infections in gingival epithelium. The Southern blot method with 32P-radiolabelled DNA probes under stringent conditions was applied to 20 interproximal gingival papillae specimens and revealed homologous EBV sequences in 4 of 10 AIDS patients as well as in 4 of 10 HIV negative patients. In order to determine whether EBV has a predilection for the gingival tissues, samples of nasal, laryngeal and oral mucosa, other than gingival mucosa, were collected from 10 HIV-negative patients undergoing surgical treatment for a variety of clinical conditions. None of these extra-periodontal mucosal specimens contained homologous EBV DNAs, except an edentulous palatal gingival specimen. With the present detection of EBV DNAs in the gingival tissues of patients undergoing surgical extractions, it would be of interest to investigate more systematically these subclinical infections in order to determine their exact implications in oral disease.

Acquired Immunodeficiency Syndrome↗
PubMed1992

Southern blot detection of human papillomaviruses (HPVs) DNA sequences in gingival tissues.

The highly sensitive and specific methods of molecular biology emphasize the frequency of subclinical infections in the genital tract tissues by the human papillomaviruses (HPVs). The purpose of this work was to investigate occult viral infections by the HPV type 6, 11, 16, and 18 in the gingival tissues. The Southern blot method with 32P-radiolabeled DNA probes applied under stringent conditions to 20 interproximal gingival papilla specimens revealed homologous viral sequences in 1 of 6 cases of adult periodontitis (HPV 16), 1 of 2 cases of rapidly progressive periodontitis (RPP) (HPV 6/HPV 11), 2 of 2 cases of acute gingivitis in psychiatric institutionalized patients (HPV 6; HPV 6/HPV 11), and 2 of 10 cases of acute gingivitis in AIDS patients (HPV 6/HPV 11/HPV 16; HPV 6). No periodontal or extra-periodontal specimen hybridized with the HPV 18 probe. Simultaneous hybridization with two or three HPV types was common (3/6 cases). The present detection of HPV 6, 11, 16 DNAs or related-DNAs in periodontal tissues without obvious clinical signs of viral infection suggests that the gingival epithelium may act as a reservoir.

Adult↗
PubMed1992

[Gingival hyperplasia secondary to the use of calcium antagonists: analysis].

Calcium antagonists are drugs restricting transmembrane calcium delivery. They possess a wide range of action against vasoconstriction and spastic reactions and were therefore initially recommended for the treatment of angina pectoris. With the increasing number and classes of calcium antagonists new therapeutic indications have emerged. Cases of gingival hyperplasia associated with their use are repeatedly reported, therefore the question deserves to be restated. The aim of the present study was to discuss the clinical, pathologic and pathogenetic features bases on an investigation carried out in a Department of Cardiology, on a case observation and on review of published cases in the international literature.

Adult↗
PubMed1991

Embryology of the hair follicle.

A study of hair follicle development has enabled us to differentiate four stages by relating them to corresponding gestation ages. Stage I of the hair bud is characterized by an epiblastic proliferation penetrating the subjacent mesenchyma at the extremity of which mesenchymal cells accumulate. This appears, at the level of the lower lip, before the 11th week of intrauterine life. Stage II of the hair bulb is reached on the 12th-13th week of intrauterine life, as soon as the distal extremity of the hair bud, which has extended, becomes depressed at the mesenchymal papilla level. Stage III is defined by the observation of hair cone and rough sebaceous glands on the 15th week of intrauterine life. Finally, stage IV shows a differentiated sebaceous gland with a hair which comes through the skin surface on the 18th week of intrauterine life.

Fetus↗
PubMed1991

Embryology and secretory activity of labial salivary glands.

This study was carried out on the heads of 20 foetuses aged between 11 and 26 weeks. Four stages were distinguished in the development of labial salivary glands, each stage corresponding to gestational age. Stage I is characterized by a localized, rounded thickening of the stomodial epiblast into the mesenchyma of the mucosal side of the lower lip. This occurs at the 9th-10th week of gestation. Stage II is reached when the epiblastic thickening assumes the form of a single cord. It is oval when sectioned transversally and is the result of the proliferation of epiblastic cells into the underlying mesenchyma during the 11th-12th week. Stage III corresponds to a branching process which takes place at the 13th week. The single cord branches to form the future secretory lobes, which rapidly assume a grape-like appearance. The number of rudimentary glands increases during the first three stages of development, i.e. as long as the first formed glands have not developed ducts. Stage IV corresponds to the process of duct formation at the 18th week. Simultaneous differentiation of acinal and duct cells is observed and this procedes the onset of secretory activity.

Basement Membrane↗
PubMed1989

[The role of cellular immunity in gingival inflammation through a study of the cells of Langerhans].

The purpose of this semiquantitative study was to evaluate the number of Langerhans cells in correlation with gingival inflammation and the use of two antisera: anti-T6 and anti-HLA/DR reacting with two different membrane antigens. Results indicate that HLA/DR is a better functional marker, and that the number of Langerhans cells is higher in the moderate inflammation of the gingiva (G.I. 1 to 2).

Adult↗
PubMed1989

Quantification of T6+ and HLA/DR+ Langerhans cells in normal and inflamed human gingiva.

Langerhans cells are dendritic non epithelial cells found in the gingiva. The latest research in immunohistochemistry suggests that they may play an important role in the cellular immune response. The purpose of this quantitative study was to evaluate the number of Langerhans cells in association with gingival inflammation and the use of monoclonal antibodies reacting with two different antigens: T6 and HLA-DR, present on the cell membrane. Results indicate that Langerhans cells are mostly T6+; but HLA-DR appears as a good functional marker. Langerhans cells may play an important role in the cellular immune response to bacterial antigens in moderate inflammation of the gingiva.

Adult↗
PubMed1987

Gingival granular cell tumor of the newborn: immunoperoxidase investigation with anti-S-100 antiserum.

The gingival granular cell tumor (GGCT) of the newborn is a rare, benign tumor, most often observed in the canine area of the maxilla of female infants. The main histologic features are not controversial and involve the occurrence of sheets of granular cells and a prominent vascular component. Conversely, ultrastructural studies agree on limited features and give rise to different hypotheses of mesenchymal origin. S-100 immunoperoxidase investigation of one case shows that, unlike those of granular cell tumor (granular cell myoblastoma) granular cells of GGCT do not react positively for S-100 protein, thus suggesting that the GGCT and the granular cell myoblastoma have a different histogenesis. It confirms also the occurrence of smaller, isolated, spindled, nongranular S-100-positive cells of indeterminate nature, distributed at the periphery of some blood vessels.

Female↗
PubMed1987

Human papillomaviruses in oral epithelial lesions. Comparative study between histopathology and immunohistochemistry in routine diagnosis.

Forty five oral papillary lesions classified clinically and histologically as condylomatous papilloma, hyperkeratotic papilloma and oral wart were subjected to histopathological evaluation and tested with Human Papilloma Virus (HPV) antiserum, in order to detect HPV group-specific antigens. The immunoperoxidase labelling technique was positive in 10% of 31 condylomatous papillomas, 22% of 9 hyperkeratotic papillomas, and 60% of 5 oral warts. No viral antigens could be detected in 4 oral fibromas used as negative controls. The study of presumed HPV cytopathogenic effects showed that koilocytosis of varying extent was regularly observed and quantified, while three types of koilocytotic cells could be identified. As it is now evident that HPVs play an important role in oral epithelial lesions, the recognition of their cytopathogenic effects in the infected oral mucosae is of increasing interest.

Humans↗
PubMed1986

[Leukoedema].

Explore the source record for details and available documents.

Humans↗
PubMed1986

Stereologic analysis of histologic parameters of a twice-recurrent ameloblastic fibroma.

The behavior of the odontogenic tumors with time remains a subject of controversy. A case of ameloblastic fibroma with two recurrences is presented. It represents further evidence of the ability of the ameloblastic fibroma to recur, although recurrences may have resulted from incomplete initial removal. The volumetric density of the odontogenic epithelium (Vvoe) was evaluated stereologically for the initial tumor and for each recurrence. Analysis of the results shows that a maturation process, which was statistically significant, occurred between the initial tumor and the first recurrence but not between the first and second recurrences.

Child↗
PubMed1986

S-100 immunolabelling of Langerhans cells in oral epithelium.

Langerhans cells (LCs) are dendritic cells usually present in the suprabasal regions of squamous epithelia remarkable by the presence of Fc IgG and C3 receptors, Ia/Dr, T-6 and T-4 antigens on their membranes. Conventional and immunohistochemical techniques for identification of LCs require special fixation procedures and are incompatible with paraffin embedding. A method for staining LCs, in routine fixed and paraffin-embedded material, based on the use of antiserum against S-100 proteins is presented. The problem arising from the simultaneous staining of melanocytes is discussed. S-100 positive dendritic cells should be considered as LCs when fulfilling 3 criteria: located in the suprabasal layers of the epithelium; the whole cell body being visible; with at least one dendritic process.

Dendritic Cells↗
PubMed1986

[Descriptive and immunohistochemical study of ghost cell keratinization in the calcifying odontogenic cyst].

The calcifying odontogenic cyst (COC) or Gorlin cyst is a rare and benign lesion most often intraosseous, although an appreciable number of cases are peripheral. Two histologic entities are described, one being cystic and the other neoplastic. The cystic type may occur as three variants. The occurrence of ghost cells, although shared with calcifying epithelioma of Malherbe, craniopharyngioma and other odontogenic tumors, represents the most conspicuous feature of the COC. Ghost cells are so called because they stain only faintly with common dies, including eosin. Although seldom studied, it is claimed that ghost cells are keratinized. However, this hypothesis is not universally accepted since electron microscopic studies give evidence that ultrastructural features of ghost cells differ from what is observed during the keratinizing process of the epidermis and oral mucosae. The present study, dealing with one case of COC, combines two complementary techniques: one a Rhodamine B keratin specific staining method and the other an immunohistochemical technique based on the use of a primary antiserum directed against high molecular weight keratins. With the Rhodamine B method, ghost cells and orthokeratinized cells of control gingiva are strongly stained while intermediate cells of the COC are less prominent. On the other hand, with the immunohistochemical technique, intermediate mediate cells of the COC are less prominent. On the other hand, with the immunohistochemical technique, intermediate cells of the COC and high level cells of control epithelium react strongly. Ghost cells of the COC are only faintly labelled and orthokeratinized cells of the control gingiva remain unlabelled. In combination with previous histochemical studies, these results confirm the occurrence of a keratinizing process.(ABSTRACT TRUNCATED AT 250 WORDS)

Fluorescent Dyes↗
PubMed1986

[Physiology of Langerhans cells and their potential role in oral pathology].

Langerhans cells represent a minor epidermal cell population in mammals. They are also observed in squamous epithelia of the oesophagus, vagina and cervix, as well as in oral epithelia. They occur in higher density in the non keratinized epithelium. These cells are characterized by a dendritic pattern, a clear cytoplasm and ultrastructurally by the presence of Birbeck granules. They are usually located in a suprabasal position. Their bone marrow origin is now well established. Surface markers and functional properties identify them as belonging to the macrophage/monocyte lineage. Langerhans cells can be identified in tissue sections by immunofluorescence or immunoperoxidase techniques using monoclonal antibodies directed against surface antigens such as class II histocompatibility antigens, T6 marker, or possibly T4 marker. There is also a cytoplasmic marker, the S-100 protein. A renewed interest in Langerhans cells comes from evidence of their role in the cutaneous immune response. At present these cells are considered as dendritic cells expressing a high density of class II histocompatibility antigens and behave as very potent antigen presenting cells that activate mainly helper T lymphocytes. However, experimental data on antigen processing and interleukin 1 secretion are still lacking. This review also examines the oral pathology literature with respect to modifications in the number or localization of Langerhans cells and their proximity to T lymphocytes, for example in lichen planus, Behcet's syndrome, erythema multiforme, gingivitis and oral carcinoma. Histiocytosis X represents a particular case in which the Langerhans cell itself is affected.

Behcet Syndrome↗