Denture plaque and palatal mucosa in denture stomatitis: scanning electron microscopic and microbiologic study

Denture plaque is an etiologic factor in denture stomatitis. In this study, denture and mucosa samples from nine patients were examined in the SEM and processed for microbiologic cultures. Denture plaque in patients with denture stomatitis showed a considerable thickness containing cocci, filaments, rods, yeasts, and desquamated epithelial cells. Some microorganisms were revealed in the connective tissue in one patient and phagocytizing polymorphonuclear leukocytes were found in the palatal mucosa of the patients with denture stomatitis.

Surface ultrastructural changes in chemically induced premalignant lesions in the hamster cheek pouch

The histopathological and topographical alterations occurring during the early stages of chemical carcinogenesis in the hamster cheek pouch using 7,12-dimethylbenz (alpha) anthracene (DMBA) were studied by light and scanning electron microscopy. At the scanning electron microscopic level, cellular overlapping and mild disturbance of intercellular bridges were noticed as early as the second week of DMBA application; these changes progressed with time. Clear epithelial dysplastic changes at the light microscopic level were detected by the sixth week of the experiment. The results of this investigation demonstrate the usefulness of scanning electron microscopy as an adjunct tool to study early alterations in cell morphology which occur in the stratified squamous epithelium of the hamster cheek pounch in response to a chemical carcinogen.

Localized oral amyloidosis: ultrastructural and immunohistochemical study

An histopathological, ultrastructural and immunohistochemical study of localized amyloidosis in the floor of mouth of a 58-year-old male in good health is reported. The lesion was composed of nodular deposits of amyloid surrounded by fibroblastic or histiocytic cells, and metaplastic ossification was seen in some deposits. Ultrastructural findings disclosed typical amyloid fibrils with felt-like structure. Closely connected with the amyloid deposits were cells with active histiocytic or fibroblastic appearance. Their cytoplasm contained amyloid fibrils. At the outermost area of the amyloid deposits, bundles of amyloid fibrils projected from these cells into amyloid deposits. Amyloid protein of the present case did not react to any antisera using anti-AA, anti-A lambda, anti-A kappa and anti-prealbumin antisera. It can be assumed that histiocytes or fibroblasts play an important role in local amyloid formation, however, the nature of amyloid fibril protein in the present case is unknown.

Nerve endings in the vermilion border and mucosal areas of the rat lip

Organized mechanoreceptors in mucosae and vermilion borders of rat lower lips were studied by light and electron microscopy. Cholinesterase histochemistry was applied to whole-mount preparations of mucosae for the light and electron microscopic identification of mechanoreceptors. Three types of lamellated corpuscles (a simple corpuscle; a coiled, simple corpuscle; and a Meissner-like corpuscle), and a unique, organized, bush-like assembly of free nerve terminals were identified. The simple corpuscles were found exclusively in the vestibular mucosa facing the incisor teeth. In contrast, bush-like endings were confined to the vestibular mucosa and to the lateral, eminent mucosa that faced the diastema. Furthermore, coiled simple corpuscles and Meissner-like corpuscles were localized in the boundary zone between the vestibular and lateral eminent mucosae and in the vermilion border. From a functional viewpoint, it is of interest that different areas of the rat lip contain different morphological patterns of mechanoreceptors.

The growth and structure of human oral keratinocytes in culture

Human keratinocytes derived from explants of cheek (buccal) mucosa grow vigorously in culture and can be subcultivated twice. The structure of the oral keratinocytes in vitro is the same in primary cultures and subcultures. The cells stratify, are characterized by well-developed tonofibrillar-desmosomal complexes, and rarely exhibit signs of terminal differentiation. Unique features of the culture system that favor keratinocyte growth are: incubation at 34 degrees C, inclusion of 0.5% dimethyl sulfoxide in the culture medium, and initiating subcultures as 5.0 mm colonies containing 100,000/20 microliter of medium. One primary culture can yield 6 first-passage subcultures, which subsequently achieve confluence in 10-12 days. Such cultures are a useful source of human keratinocytes that stratify but generally do not undergo terminal differentiation.

Evaluation of replica techniques for the surface ultrastructure of rodent and human palatal mucosa

Two replicating techniques currently used for scanning electron microscopy were investigated qualitatively and quantitatively. The most accurate and reliable replicating material was an epoxy resin; this was superior to copper plating as the model material, despite some dimensional inaccuracies. The selected method was then used to obtain accurate elastomeric replicas of rodent and human palatal mucosa. Salivary-duct openings, epithelial cell boundaries, desquamating cells and cell-surface micropits were identified. In some areas, coccal organisms could be seen colonizing the epithelial surface.

Intracytoplasmic inclusion bodies associated with vesicular, ulcerative and necrotizing lesions of the digestive mucosa of a roedeer (Capreolus capreolus L.) and a moose (Alces alces L.)

At post-mortem examination of a roedeer and a moose, ulcerative and necrotizing lesions were observed in the digestive mucosa.

Both animals were serologically positive for Bovine Viral Diarrhea Virus antibodies. Histological examination revealed intra- and intercellular oedema in stratum germinativum and spinosum, formation of vesicles and ulcers, and intracytoplasmic inclusion bodies in numerous epithelial cells of mainly stratum germinativum.

Electronmicroscopy confirmed the histological findings and demonstrated inclusion bodies containing a granular electron dense material encircled by a single-layer membrane. Virus particles were not found.

Electron microscopic observation on the epithelial-connective tissue junction of pemphigus vulgaris. A case report

An electron microscopic observation on the erosive buccal mucosa of a buccal mucosa of a patient with typical pemphigus vulgaris was carried out. The ultrastructural features of the basal cells and the basal lamina in the advanced oral lesion varied from section to section of the biopsy specimen. The basal lamina showed various morphologic alterations indicating the presence of both destructive and regenerative processes in different sections. The filamentous bodies were also observed both in the basal cell layer and in the upper lamina propria.

The micronucleus assay in exfoliated cells of the human buccal mucosa

The frequency of micronuclei resulting from chromosome breaks, and that of micronuclei deriving from spindle disturbances was determined in exfoliated cells of the human buccal mucosa in 50 normal individuals. Several confounding factors, such as age, smoking habits, alcohol consumption, etc., were taken into account. While the frequencies of micronuclei resulting from chromosome breaks and of cells with this kind of micronuclei were about double in smokers as compared with non-smokers, the difference being highly statistically significant, the frequencies of cells with spindle disturbances were almost the same in the two groups. No statistically significant correlation was found for any of the other variables examined. In two patients suffering from cancer of the oral cavity the variation of the frequency of the micronuclei during the progress of radiotherapy and following its interruption was determined. It was found that gamma rays induced only micronuclei resulting from chromosome breaks, whose frequency increased linearly with the applied dose, and was lowered to the initial background level 7-12 days after the end of radiotherapy.

Oral hairy leukoplakia: ultrastructural features

Ten instances of a white plaque of the lateral tongue unique to homosexual males and referred to as oral hairy leukoplakia were analysed ultrastructurally. The surface epithelial layer exhibited extracellular, intracellular and intranuclear penetration by hyphae of Candida albicans, sometimes accompanied by coccobacilli in the extracellular space. The subcorneal epithelial layer included koilocytoid ballooned cells which had a paucity of cytoplasmic organelles and displayed condensation and emargination of the chromatin. Cells that exhibited these nuclear changes were found to be infected by a herpes-type virus which was visualized by electron microscopy in all ten cases. Clusters of nucleocapsids (86-110 nm in diameter) occurred in the nuclei and enveloped virions (111-175 nm in diameter) occurred in the cytoplasm and extracellular spaces. Virions showed budding from the nuclear envelope. Bundles of tubular structures (20 nm diameter) arranged in parallel occurred in the cytoplasm of some koilocytoid cells. There was no evidence by electron microscopy of the presence of papilloma virus within koilocytotic nuclei.

Laser-induced alterations in rat oral mucosa

The alterations during healing in laser and scalpel incised palate and tongue mucosa were studied in 37 Spraque-Dawley rats by taking specimens for light and electron microscopic inspection immediately and 4, 7, 11 and 21 days after the treatments. The laser incision differed from the conventional incision: it was horizontally broader, more superficial, not bleeding and contained some charred and necrotic tissue particles; there were more inflammatory cells during healing, and the healing was slightly retarded. The damaged area around the laser incision was very narrow. In EM, the lasered areas showed total cell disruption with no morphologic details seen at the treated site. Adjacent to those sites, charred-appearing particles were seen scattered and embedded also in the connective tissue. The most resistant cell organelles against laser-caused disruption were desmosomes and nuclear membranes. After 21 days' observation the ultrastructural study still revealed cell damage even though the reepithelialization as such seemed to be complete.

Transplant of oral mucosal epithelium to rabbit ocular surface wounds in vivo

Sheets of epithelium freed of underlying connective tissue and basal lamina with dispase II were obtained from explants of rabbit oral mucosa. Epithelial sheets were then sutured onto abraded (basement membrane intact) or keratectomized corneal-limbal zones or abraded central corneas of anesthetized rabbits. To develop the procedure, allografts to abraded (N = 13) and keratectomized wounds (N = 3) on the corneal-limbal zone were done. All allografts were retained on the wound bed until the experiment was terminated or rejection occurred. Prior to rejection, eyes were uninflamed and quiet. Allografts on central avascular corneal wounds (N = 8) were not maintained. Autografts (N = 4) sutured to corneal-limbal abrasion wounds were maintained until animals were killed at the end of the experiment, 22, 26, 60, and 120 days after transplant. Eyes were uninflamed and quiet. A fine vascular bed developed under both allografts and autografts in the peripheral cornea. Grafts maintained some histologic characteristics of oral mucosal epithelium, even after four months. These data indicate that it is feasible to transplant oral mucosal epithelium to corneal-limbal ocular surface wounds and that the grafts will be maintained. Such transplants are, however, not maintained over central, avascular corneal regions.

Re-innervation pattern of heterotopically transposed lingual flaps

Pedicled tongue flaps have proved to be an effective method of repairing defects due to tissue loss in the oral cavity. No histological investigations have been done in respect of the longterm fate of these flaps after section of their nutrient pedicle. The histological pattern of the re-innervation process of heterotopically transposed lingual flaps in the oral cavity is evaluated in this paper. Two cases are reported: in the first, the tongue flap was used to repair the vermilion of the lower lip and in the second, for the closure of a post-traumatic defect of the hard palate. The histological findings are similar in the two cases: myelinated and unmyelinated fibres, free nerve endings and encapsulated receptors are present.

Pigmentary changes in rat oral mucosa following antimalarial therapy

Pharmacogenic pigmentation of the oral mucosa has been reported following the use of a number of anti-malarial drugs. The nature and distribution of the pigment is inconclusive in the literature. The aim of the present study was to document pigment deposition within the oral mucosa of DA rats following prolonged chloroquine and pyrimethamine administration. The drugs were given as a combined dosage and separately to different groups via stomach gavage tube. After 12 weekly administrations the palatal mucosa was examined histochemically and ultrastructurally for changes in numbers and size of active melanocytes using the dopa-oxidase technique. The serum was analysed for changes in ACTH and testosterone levels. Morphometric analysis of cells incubated for dopa-oxidase showed a significant increase in the size of dopa positive cells with both drugs but an increase in the number of active melanocytes with chloroquine only. Serum levels of ACTH remained unchanged with both drugs but pyrimethamine caused an elevation in testosterone.

Generalized argyrosis in man: neurotological, ultrastructural and X-ray microanalytical findings

Generalized argyrosis can produce a number of abnormalities, including skin discoloration, liver and kidney dysfunction. We describe a patient with generalized argyrosis following long-term self-treatment with oral silver intake, in whom skin discoloration, progressive taste and smell disorders, vertigo and hypesthesia were observed. These findings were confirmed by chemosensory tests and electrophysiological investigations. The development of hypogeusia was assessed by subjective tests, while the progression of hyposmia was followed by recording olfactory evoked cortical potentials. Light and electron microscopy of tissue samplings demonstrated electron-dense mineral deposits in basal membranes, in macrophages, in the perineurium of peripheral nerves, along elastic and collagenous fibers, and in necrotic cells of the oral submucosa. Silver and sulfur deposits in affected tissues could be defined by X-ray microanalysis. The quantitative ratio between silver and sulfur in involved tissues was similar to that of an inorganic silver-sulfide (Ag2S) standard. The minute increase in the sulfur content when compared to the inorganic standard suggested a sulfur containing organic matrix of the tissue precipitates. Our findings indicate that the affinity of silver for membrane and neuronal structures and the deposition of silver as an insoluble compound (Ag2S) induce the progression of clinical disease.

Nodular fasciitis of the upper labial fascia: cytometric and ultrastructural studies

The rare case of nodular fasciitis in the upper labial fascia is reported. Light microscopic, electron microscopic and cytometric studies were performed. The histopathology corresponded to intermediate and reactive types in the Price and Bernstein classification. Cytometric study of evaluating DNA of fibroblasts revealed a high distinct peak in myxoid and inflammatory areas. Ultrastructurally, fibroblasts and myofibroblasts were identified in the lesion. Reported Japanese cases of orofacial nodular fasciitis are reviewed and compared with the European-American literature.

Intra-oral benign solid oncocytoma

Oncocytomas are extremely uncommon in the intra-oral minor salivary glands, they are rarely reported in the literature and the histopathology and clinical details are inadequately documented. This has led to uncertainty with regard to the behaviour and prognosis of this type of lesion. A case of benign solid oncocytoma arising from intra-oral minor salivary glands is reported here with a brief review of the pertinent literature.

The verruciform xanthoma. A review and report of eight new cases

The verruciform xanthoma (VX) is an uncommon lesion that most often occurs in the oral cavity but occasionally may be seen in other sites. Eight new cases of VX of the oral mucosa are presented. The histologic features are discussed and theories of etiology and pathogenesis are reviewed. The VX appears to be a reactive lesion in which the xanthoma cells arise secondarily to degeneration of cells in the overlying epithelium.

Analog enhancement of videomicroscope images

A simple, inexpensive technique for enhancing the contrast and resolution of videomicroscope images has been developed. The system has manual controls for gain and pedestal (black level) which permit expansion of low contrast images to the full white-to-black video range. Analog delay-line based circuits are used to sharpen the edges and enhance fine details in the image. These circuits also produce an effective increase in the information content of the image by selectively amplifying low amplitude, high frequency components of the video signal. When live, unstained cells were examined at high magnifications, cytoplasmic structures which were only faintly visible in the unenhanced image became clear. The images of fluorescent objects appear in pseudo-relief, which improves visibility even in the presence of background fluorescence. The system enhances images by performing signal processing functions that otherwise require expensive digital image processing equipment.

Sex determination from buccal mucosa and hair root by the combined treatment of quinacrine staining and the fluorescent Feulgen reaction using a single specimen

In order to determine sex using a single specimen, buccal mucosa and hair roots obtained from male and female individuals were used. The specimens were first stained with quinacrine for the detection of the Y-chromatin, and subsequently were stained by the fluorescent Feulgen reaction using acriflavine for the detection of the X-chromatin. In the male specimens, the frequency of fluorescent spots of quinacrine-positive bodies was high, whereas that of acriflavine-positive spots was low. On the other hand, in the female specimens, the frequency of quinacrine-positive spots was very low, while that of the acriflavine-positive spots was high. These specimens were air-dried and were allowed to stand at room temperature for periodical observations. The result was that sex difference was distinguishable for 4 months by the combined treatment method.