Mast cells in oral lichen planus

Biopsies from lichen planus affected oral mucosa were compared with biopsies from healthy oral mucosa, in terms of the number of mast cells, their location and their morphological alteration at the light microscopic and electron microscopic level. In comparison with the normal oral mucosa an increased number of mast cells was found below the subepithelial infiltrate. This difference was statistically highly significant (p less than 0.001). In the deeper part of the infiltrate mast cells were found to contain granules which presented an altered morphology upon electron microscopic examination. These cells had many of the ultrastructural changes that have been reported for mast cells undergoing degranulation. The present morphological observations suggest that mast cells participate in the recruitment of lymphocytes to the subepithelial infiltrate.

Cylindrical cell papilloma. Report of a case with light and ultrastructural analysis

The clinicopathologic features of an additional case of cylindrical cell papilloma are reported. This tumor is relatively rare, with approximately twenty cases recorded under that name in the literature. Surgical correction of papillomas in the nose and paranasal sinuses is discussed. Ultrastructural analyses suggest that cylindrical cell papilloma may possibly be an oncocytic lesion and thus different from the inverted and fungiform types.

Retroviruses in Kaposi's sarcoma in acquired immune deficiency syndrome (AIDS)

The ultrastructure of Kaposi's sarcoma (KS) of the oral mucosa in patients with acquired immune deficiency syndrome (AIDS) was examined electron microscopically. The tumour consisted of pleomorphic vascular endothelial structures and spindle cell formations. The KS cells contained characteristically numerous multivesicular bodies, a large number of tubuloreticular structures and abundant Weibel-Palade bodies in their cytoplasm. Virus particles, 100-120 nm in diameter, were observed budding from the plasma membrane or as free particles already separated from the plasma membrane. Many mature virions manifested a dense cylindrical-shaped core. These virus particles and the human T-cell lymphotropic retroviruses subgroup HTLV-III are ultrastructurally identical. This report is based on recent immunological research.

The binding of Pseudomonas aeruginosa outer membrane ghosts to human buccal epithelial cells

The binding of outer membrane (OM) ghosts derived from Pseudomonas aeruginosa strain 492c to human buccal epithelial cells (BECs) was examined. Electron microscopic examination of the binding of OM ghosts to BECs revealed direct OM ghost-BEC interaction. Equilibrium analysis of the binding of OM ghosts to trypsinized BECs employing the Langmuir adsorption isotherm indicated the number of binding sites (N) to be 1.3 X 10(-4) micrograms protein per BEC with an apparent association constant (Ka) of 3.4 X 10(-2) mL/microgram protein. The Langmuir analysis of binding of OM ghosts to untrypsinized BECs was complex, suggesting two possible classes of receptors, a high affinity-low copy number class (Ka, 7.8 X 10(-2)mL/microgram protein; N, 8.6 X 10(-5) microgram protein per BEC) and a low affinity-high copy number class (Ka, 3.7 X 10(-3)mL/microgram protein; N, 9.2 X 10(-4)microgram protein per BEC). Sugar inhibition studies incorporating D-galactose enhanced binding to each BEC type. N-Acetylneuraminic acid and N-acetylglucosamine both enhanced binding of OM ghosts to untrypsinized BECs, while inhibiting binding to trypsinized BECs. D-Arabinose inhibited binding to both BEC types. Binding of OM ghosts to both BEC types was greatly inhibited by D-fucose, while L-fucose only greatly inhibited binding to untrypsinized BECs. These sugar inhibition data demonstrated a difference in the binding of OM ghosts to trypsinized and untrypsinized BECs and possibly reveal the nature of the receptor(s), free of possible bacterial metabolic effects.(ABSTRACT TRUNCATED AT 250 WORDS)

A scanning electron microscopic study of fissured tongue

In this study, scanning electron microscopy was used to describe the surface morphology of fissured tongue. Tissue samples from the anterior part of the tongue were taken from 15 patients with fissured tongue. The formalin-fixed samples were processed routinely for scanning electron microscopy. Typically, the surface of a fissured tongue was covered with hairless papillae of various sizes. The biggest papillae were larger than the body of a normal filiform papilla, and the apex was rounded and rough. On the other hand, some of these papillae had a few hairs and resembled normal filiform papillae, but were flatter. In addition some papillae formed only slight elevations on the tongue mucosa, which was smooth and contained some desquamating cells. The walls of the fissure found in macroscopical examination consisted of very low elevations of the smooth mucosa with some desquamating cells. At high magnification the superficial cells of the epithelium were polygonal. On their surface there were branching or parallel microplicae, which were often broken. Only occasionally superficial cells of the large papillae had a pitted appearance. The knob-like structures found among the microplicae and small cracks between the epithelial cells are discussed from the standpoint of the pathogenesis of fissured tongue.

Canalicular adenoma of the buccal mucosa. An ultrastructural and histochemical study

A canalicular adenoma that occurred in the minor salivary glands of the buccal mucosa in a 62-year-old black man was examined by electron microscopy and histochemistry. The ulcerated bowl-shaped tumor consisted mostly of ductlike tubules of columnar and cuboidal epithelial tumor cells which resembled intercalated duct cells ultrastructurally. Tumor cells resembling myoepithelial cells were not associated with these tubules. Less frequently, there were narrow tubules and cords adjacent to the capsule. Occasional cells in these cords contained variable amounts of microfilaments, often associated with focal densities, and thus resembled myoepithelial cells in varying stages of differentiation. Other noteworthy ultrastructural findings in this neoplasm included marked replication of the basal lamina of capillaries and the presence of a single, luminally oriented cilium in a tumor cell lining a tubule.

Scanning electron microscopic study of surface of human oral mucosa

The surface ultrastructure of the healthy oral mucosa of humans was studied using SEM as follows: dorsum of the tongue (10 specimens), buccal mucosa (5), floor of the mouth (3), hard palate (5), and gingiva (10). One part of each formalin-fixed sample was processed routinely using the system of critical point drying for scanning electron microscopy. The other part of the specimen was embedded in paraffin blocks and stained with hematoxylin-eosin for light microscopy. With SEM at low magnification, the surface structure of the oral mucosa at different areas of the oral cavity was smooth with some desquamating cells. Only the tongue mucosa with its papillae formed a specialized mucosa. The hairs of the filiform papillae were covered by microorganisms, whereas on the oral mucosa there usually was little or no colonization by microorganisms. At high magnification, the surface structure of the superficial epithelial cells was pitted or microplicated. On keratinized epithelium the surface structure was pitted, whereas on non-keratinized epithelium it was microplicated. On cell boundaries some variation could also be seen; in keratinized epithelium these boundaries were overlapping and in non-keratinized epithelium they were tight.

[Morphology of the oral mucosa in rats exposed to increased phosphorus levels]

The experiments on rats kept for 1, 2, 3 and 4 months in phosphorous-producing workshops revealed the influence of elementary phosphorous and its nonorganic derivatives on the mouth mucosa tissues. At the early stages of the experiments the above agents caused the increase in the number of the epithelial layer cell elements, and strengthening of the keratosis process, leading to the development of hyperkeratosis. By the end of the experiment the development of dystrophic and atrophic processes in the epithelium were observed, which sometimes caused thinning of the epithelial layer. The connective tissue of submucous basis was characterized by microcirculation disorders and dystrophic disturbances of blood vessel walls becoming more pronounced by the end of the experiment.

A light and electron microscopic study of lamellated nerve endings found in the rat cheek mucosa

Lamellated nerve endings in the cheek mucosa of fifteen adult Sprague-Dawley rats were studied with light and electron microscopes. Serial sections revealed that the terminal axon of the lamellated nerve endings is in the central portion, and that the inner core is made up of two stacks of lamellae. These are characterized by many corpuscles located within a single papilla, which shows structural specializations at several levels. Electron microscopy showed that the corpuscles are circular in shape and that the lamellar sheets possess a rich rough endoplasmic reticulum, mitochondria and numerous glycogen-like granules. Numerous bundles of collagen fibers and an amorphous substance are located in the interlamellar spaces. The axon terminal is characterized by the presence of neurofilaments, neurotubules and mitochondria. The capsule consists of several laminae formed by cytoplasmic extensions of perineural cells presenting many caveolae, mitochondria, rough endoplasmic reticulum profiles and microfilaments.

Evidence for chromosome instability in vivo in Bloom syndrome: increased numbers of micronuclei in exfoliated cells

The incidence of exfoliated epithelial cells containing micronuclei was determined in two small human populations, one homozygous and the other heterozygous for the Bloom syndrome gene (bl). The objectives of the study were two: to learn whether the chromosome instability featured so prominently by Bloom syndrome (BS) cells proliferating in vitro also occurs in vivo, and as part of a broad survey of various cancer-prone populations, to determine whether estimating micronucleus frequencies in exfoliated cell samples might be useful for identifying individuals with genetically determined chromosome instability. Eight individuals homozygous (bl/bl) for the BS gene, i.e., persons with the clinical syndrome, were examined, along with 11 obligate heterozygotes (bl/+), parents of affected persons. Exfoliated cells were obtained from two sites, the oral cavity and the urinary tract. Striking and statistically highly significant elevations in the frequencies of cells with micronuclei were observed in cells from both sites in bl/bl individuals compared to that in bl/+ (P less than 0.001) and in a control population, indicating that chromosome instability occurs in vivo in BS. In contrast, micronucleus frequencies at either site did not differ significantly between bl/+ individuals and the control population. This survey, in combination with similar earlier ones of populations predisposed to cancer not on a genetic basis but because of exposure to some environmental carcinogen, suggests that the exfoliated cell micronucleus test identifies individuals whose somatic genetic material has, for either genetic or environmental reasons, been damaged in a way that produces chromosome breakage and rearrangement.

An ultrastructural morphometric study of cellular and nuclear volume alterations during experimental oral carcinogenesis

Cellular and nuclear pleomorphism are features of epithelial dysplasia, a premalignant alteration found in many stratified squamous epithelia including those of the oral mucosa. In the present report we have applied morphometric techniques to evaluate alterations in cellular and nuclear volume during epithelial differentiation in experimentally-induced oral carcinogenesis. Hamster cheek pouches treated with DMBA were biopsied and assigned to hyperplasia, dysplasia and carcinoma groups with untreated pouches being used as controls. Following a rigorous sampling scheme, electron micrographs from defined basal, spinous and granular strata were obtained and cellular and nuclear volumetric estimates obtained by a combination of direct measurement and stereological intersection counting. In all strata, nuclear, cytoplasmic and cellular volumes were lowest in the normal control group and were increased in all experimental groups. Volumetric estimates obtained for carcinogen-treated groups were generally between 2 to 3 times higher than for the control group which indicates that cellular and nuclear hypertrophy occurs in conjunction with the epithelial hyperplasia and proliferation induced by the chemical carcinogen. We also describe the application of the pathological alteration ratio (PAR), a parameter which is independent of methodological variables, and which was consistently elevated in our experimental study. This was also applied to a number of reports in the literature which describe morphometric alterations in cellular or nuclear parameters in a variety of human lesions. Within any particular group of lesions, PAR values were generally higher for carcinomas than for other benign conditions. We conclude that cellular and nuclear hypertrophy occurs not only during experimental carcinogenesis but also in human benign and malignant lesions. With the advent of computer-based automated image analysers, measurements of certain structural features on sectioned tissues may have a role in histopathological diagnosis.

Ultrastructural findings of muscle degeneration in oral submucous fibrosis

Muscle changes were investigated ultrastructurally in 2 groups of patients having oral submucous fibrosis. One group was from patients with no evidence of restricted mouth opening and the other was from patients with restricted mouth opening. Electronmicroscopically, the majority of muscle fibres taken from the first group appeared normal with only occasional muscle fibres showing accumulation of homogeneous material and compression of the sarcomeres closest to this material. In contrast, the tissues from patients with restricted mouth opening showed severe changes and necrosis in a high proportion of muscle fibres. The necrotic muscle fibres exhibited complete loss of their plasma membrane, but in which the outline was maintained by an intact basal lamina. It is suggested from this study that restricted mouth opening in submucous fibrosis might depend not only on the subepithelial fibrosis but also on the extent of muscle degeneration.

A histologic study of epithelial dysplasia in oral lichen planus

One hundred cases of oral lichen planus were reviewed together with 100 nonspecific oral mucosal inflammatory lesions as a control group. The presence of dysplasia was noted, using well-established histologic criteria. Mild dysplasia was found in 57% of cases, moderate dysplasia in 9%, and severe dysplasia in 2% of cases. In the control group, mild dysplasia was observed in 32% of cases, moderate in 10%, and severe dysplasia was not present. It is suggested that, while mild or moderate dysplasia may not indicate precancerous potential, severe dysplasia in lichen planus may signify the development of a precancerous lesion.

Schistosoma mansoni: an ultrastructural examination of skin migration in the hamster cheek pouch

The hamster cheek pouch has been used to investigate the skin migration of schistosomula at the ultrastructural level. Parasites have been observed up to 72 h post-infection. Despite rapidly reaching the epidermal basement membrane schistosomula remain in an epidermal location for at least 40 h post-infection, by which time the acetabular glands and their ducts have been lost and the transformation from cercaria to schistosomulum completed. Entry into the dermis and exit from the skin via the blood vessels is therefore by mechanical means or by lytic secretions emanating from a source other than the acetabular glands. The head gland which persists in the dermal schistosomula is a probable source of such secretions. The observations suggest that the apical area and musculature of the head capsule are important in gaining access to the lumen of blood vessels.

X-ray microscopy: experimental results with the Göttingen X-ray microscope at the electron storage ring BESSY in Berlin

An X-ray microscope and X-ray microscopy experiments with biological specimens are described. The experiments have been performed with a resolution of about 0.05 micron using the synchrotron radiation of the electron storage ring BESSY.