Biomedical subjects
R A Monteil
Publications and source records attributed to R A Monteil.
[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).
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.
[A plea for vaccination against hepatitis B: importance or protocol].
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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.
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.
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.
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.
[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)
[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.
[The Langerhans cell: a vector of periodontal immunity?].
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[Geographic tongue (exfoliation of areas of the tongue)].
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Squamous odontogenic tumor related to an unerupted lower canine.
A new case of squamous odontogenic tumor (SOT) is presented. This is the seventeenth case of SOT to be reported and the first reported case related to a lower unerupted canine. A review of the literature reveals the extreme variability of the clinical and radiologic features of this tumor. Conversely, the microscopic characteristics of SOT are clearly defined: numerous islands of benign squamous epithelium scattered in an apparently mature connective tissue, absence of peripheral columnar cells with palisading nuclei, and absence of stellate reticulum. Keratin pearl formation, intraepithelial microcyst formation, and calcification are present to a variable extent. A circular arrangement of fibroblasts and fibrous condensation and/or hyalinization are observed around some epithelial islands, suggesting a reaction of the connective tissue to the epithelial proliferation. The observation of small epithelial islands near the apical surface of the retained tooth supports the theory that the tumor originates from Malassez's rests. The treatment of choice seems to be conservative, with thorough enucleation, but it should be borne in mind that multifocal cases have been described.
[Preliminary medical survey: long or short form?].
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[Oral leukoplakia: clinical or histologic entity?].
The term leukoplakia was coined by the Hungarian Schwimmer to describe the clinical aspect of white lesions appearing on the mucosae. Unfortunately, the use of leukoplakia for diagnostic purposes in oral pathology has led to so much confusion that diagnosis of leukoplakia has been established, using strict histological criteria, for lesions that did not appear as white patches. Moreover, it is known that what has previously been termed leukoplakia is now shown to consist of several distinct entities. The current clinical concept was established by W.H.O. Leukoplakia: a white patch or plaque that cannot be characterized clinically or pathologically as any other disease. Analysis of histological criteria and classification appearing in the literature and review of the cell and tissue abnormalities reveal that many conditions from hyperkeratosis to epidermoid carcinoma can occur within clinical leukoplakia. Orthokeratosis or hyperorthokeratosis is often found in leukoplakia simplex and leukoplakia verrucosa while parakeratosis or hyperparakeratosis is mainly observed in cases of erosive or speckled leukoplakia. Speckled leukoplakia (nodular white excrescences on an erythematous base) is the clinical type involving the more frequently severe dysplasia and carcinoma. This study demonstrate that the term leukoplakia only describes clinical conditions and does not carry any histological connotation
[Fordyce's spots: disease, heterotopia or adenoma? Histological and ultrastructural study].
Fordyce spots are sebaceous glands without hair follicles, most often located under the epithelium of the cheek and free lip border. These glands, present in 80 to 95% of adults, according to the localization, cannot be considered as ectopic. Along the same lines, these spots are neither a disease, a lesion or an adenoma. These glands are acino-tubular and distributed in clusters. They are connected to the covering epithelium by a duct with a keratinizing stratified epithelium. By analog to what has been done in the skin, the acinous cells can be artificially classified in three groups: basal germinative cells partially differentiated intermediary cells and totally differentiated preductal cells. With PAS-Mac Manus, the peripheral cells are characterized by a reduced cytoplasm, the scarcity of organelles, as well as the presence of tonofilaments and desmosomes. The intermediary cells have a low nucleus-cytoplasm ratio. While keeping their epidermal characters, they become rich in lipid droplets of variable sizes and are closely related to numerous mitochondria. The cytoplasm of completely differentiated cells, with unrecognizable organelles, are invaded by large lipid globules. In the periacinous connective tissues, fenestrated capillaries are observed.
[A new technic for the radiography of the mandibular ascending rami using the Panorex].
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