[Comparative analysis of cytogenetic instability in buccal epithelial cells in the urban and rural dwellers of the Republic of Bashkortostan]

The frequency of cytogenetic instability in buccal epithelial cells was studied in the urban and rural dwellers of the Republic of Bashkortostan. A total of 26256 cells from 24 students who had been born in Ufa and 26951 cells from 25 students who had lived in a rural area before entering the Institute were analyzed. The students' age was 17 to 19 years. The study has indicated that cytogenetic instability and other types of karyological anomalies in the buccal epithelial cells of rural and urban dwellers depend on gender and environmental factors.

Scanning electron microscopic study of the tongue in the rainbow lorikeet (Trichoglossus haematodus)

The dorsal lingual surfaces of rainbow lorikeet (Trichoglossus haematodus) were examined by scanning electron microscopy. Macroscopically, the tongue of the rainbow lorikeet has a finger-like shape. Three parts are distinguished in the dorsal surface of the tongue: the apex, body, and root of the tongue. The apex of the tongue has numerous processes inclined toward medial side from lateral side. These processes are rod-like structure and smooth surfaces. Many grooves are observed in both lateral sides of the lingual body. A large opening of the lingual gland exists in central part of the lingual root and some large openings of the lingual glands exist in both lateral sides of the lingual root.

Ultrastructural localization of salivary mucins MUC5B and MUC7 in human labial glands

As a result of their presence throughout the mouth in the submucosa or between muscle fibers, minor salivary glands secrete directly and continuously into the oral cavity, providing mucosal surfaces with highly glycosylated proteins that are active in bacterial aggregation and in oral tissue lubrication. In this study, we investigated the ultrastructural localization of the MUC5B and MUC7 mucins in human labial glands by means of a postembedding immunogold technique. Thin sections of normal human labial glands, obtained during surgery, were incubated with polyclonal antibodies to human salivary mucins MUC5B and MUC7, and then with gold-labeled secondary antibodies. Specific MUC5B reactivity was found in the secretory granules of mucous cells of all glands examined, and was associated with the luminal membrane of duct cells. MUC7 labeling was observed in the granules of both mucous and seromucous secretory cells of the glandular parenchyma. Quantitative analyses demonstrated that seromucous granules have higher immunogold labeling densities for MUC7 than mucous granules. Our immunohistochemical data extend the results of previous light microscopic studies of MUC5B and MUC7 localizations, pointing out the significant contribution of human labial glands in the secretion process of these two mucins.

Histological evaluation of buccal penetration enhancement properties of chitosan and trimethyl chitosan

The aim of the present work was to compare the penetration enhancement properties of chitosan hydrochloride (HCS) both as a polymeric solution and as a nanoparticulate system with that of trimethyl chitosan hydrochloride (TMC) on buccal mucosa. The hydrophilic high molecular weight fluorescein isothiocyanate dextran (FD4; 4400 Da) was used as a macromolecule model. The mechanism involved in the HCS (solution and nanoparticles) and TMC solution penetration enhancement was investigated on pig buccal mucosa, characterized by having stratified epithelium and lacking in tight junctions. The permeation/penetration of FD4 and the change in morphology and histology of the mucosa after contact with the polymers were assessed: the experiments were performed ex-vivo by applying the formulations on excised porcine buccal tissue. For the morphology and the histology studies, the epithelial cell layers from freshly excised pig buccal mucosa were analysed with light microscopy by means of routine histopathology analysis (haematoxylin and eosin staining and Toluidine blue staining) and immunohistochemistry reactions. The organization of desmosomal junctions was assessed by means of an immunochemical reaction on desmosomes and transmission electron microscopy. Confocal laser scanning microscopy (CLSM) was used to find evidence of the location of FD4 in the tissue. Furthermore, the increase of the FD4 apparent permeability coefficient was quantified by means of Franz diffusion cells using isolated buccal epithelium to demonstrate the penetration enhancement properties of the polymer systems. Morphological analysis, performed by light microscopy, transmission electron microscopy and CLSM, suggests a similar mechanism of penetration enhancement for both HCS and TMC solutions and for HCS nanoparticles. Such a mechanism probably involves a repackaging of the epithelial cells up to the basal membrane and a partial disarrangement of desmosomes. The cell viability and the nuclear integrity indicated on the semi-thin section stained with Toluidine blue and by CLSM analysis, respectively, suggest that HCS as a polymer solution and a nanoparticulate system, and TMC polymer solution, do not cause cell damage. Trimethyl chitosan and chitosan nanoparticulate systems were able to increase FD4 permeation across buccal epithelium to a greater extent than the chitosan solution.

A Scanning Electron Microscopic Study of the Dysplastic Epithelia Adjacent to Oral Squamous Cell Carcinoma

By light microscopy, the dysplastic oral epithelia due to the neoplastic processes are similar to epithelial changes due to the inflammatory processes. Scanning electron microscopy may elucidate the different surface changes between the two. The aim of this study was to examine the surface appearances of the dysplastic oral epithelia adjacent to oral squamous cell carcinoma to see if there are any surface changes. A total of 2 specimens, one specimen from each patient with oral squamous cell carcinoma, were used for this study. Each specimen was divided in two. One half was prepared for light microscopy and the other half was prepared for scanning electron microscopy. Light microscopically, the epithelia showed mild dysplasia. By scanning electron microscopy, the keratinized cells showed irregular microridges surrounding pits, which were variable and irregular in size and shape, and the nonkeratinized cells showed parallel microridges with irregularly widened intervals between each microridge. Irregular, broad, and partly swollen microridges and irregular short, stubby surface projections were also seen. The oral epithelia adjacent to oral squamous cell carcinoma showed mild dysplasia light microscopically but appeared abnormal by scanning electron microscopy. The abnormal epithelial cells showed pleomorphism, irregular and disoriented microridges, and abnormal surface microstructures.

A Comparative Study of the Surfaces of Normal Oral Epithelia and Inflammatory Hyperplasias by Scanning Electron Microscopy

The oral epithelia may show epithelial changes induced by the inflammation of the underlying lamina propria. Light microscopically, the epithelial changes are similar to epithelial dysplasia seen in a premalignant lesion. A scanning electron microscope permits a resolution higher than that of a light microscope. Therefore, it may elucidate the changes observed light microscopically. The purpose of this study was to examine the surface changes of the epithelia of parulides (gum boils) compared with those of normal oral epithelia to see if there were any surface changes due to the underlying inflammatory processes. A total of 3 specimens (1 buccal mucosa, 1 gingiva, and 1 hard palate) taken from 3 patients, one specimen from each patient, were used as controls. A total of 2 parulides from 2 patients, 1 specimen from each patient, were used as experimentals. Each specimen was cut in two. One half was prepared for light microscopy and the other half was prepared for scanning electron microscopy. Light microscopically, it was confirmed that the buccal mucosa was nonkeratinized, the gingiva was parakeratinized, and the hard palate was orthokeratinized. The epithelium of the parulis was nonkeratinized to parakeratinized with increased intercellular spaces and distinct epithelial changes similar to epithelial dysplasia. By scanning electron microscopy, the nonkeratinized mucosa (buccal mucosa) showed that most of the ridges ran parallel to each other and the parakeratinized mucosa (gingiva) and the orthokeratinized mucosa (hard palate) exhibited ridges surrounding uniform pits. The surface of the parulis of the first patient showed relatively smooth areas with residual pits, reminiscent of that of keratinized mucosa, and the surface of the parulis of the second patient showed relatively smooth areas with residual parallel ridges, reminiscent of that of nonkeratinized mucosa. Light microscopically, the oral epithelia overlying the intensely inflamed lamina propria showed distinct epithelial changes similar to epithelial dysplasia seen in a precancerous lesion but appeared normal except for markedly decreased numbers of microridges by scanning electron microscopy.

TRPV2 expression in rat oral mucosa

The oral mucosa is a highly specialised, stratified epithelium that confers protection from infection and physical, chemical and thermal stimuli. The non-keratinised junctional epithelium surrounds each tooth like a collar and is easily attacked by foreign substances from the oral sulcus. We found that TRPV2, a temperature-gated channel, is highly expressed in junctional epithelial cells, but not in oral sulcular epithelial cells or oral epithelial cells. Dual or triple immunolabelling with immunocompetent cell markers also revealed TRPV2 expression in Langerhans cells and in dendritic cells and macrophages. Electron microscopy disclosed TRPV2 immunoreactivity in the unmyelinated and thinly myelinated axons within the connective tissue underlying the epithelium. TRPV2 labelling was also observed in venule endothelial cells. The electron-dense immunoreaction in junctional epithelial cells, macrophages and neural axons occurred on the plasma membrane, on invaginations of the plasma membrane and in vesicular structures. Because TRPV2 has been shown to respond to temperature, hypotonicity and mechanical stimuli, gingival cells expressing TRPV2 may act as sensor cells, detecting changes in the physical and chemical environment, and may play a role in subsequent defence mechanisms.

Ultrastructural and molecular-biological features of inflammatory-destructive processes in pathology of parodontal complex in children

In children aged 11-15. under mild and moderate stage parodontitis the ultrastracture and Citokeratines 10/13 and 14 expression in epithelial lining of oral mucosa were analyzed: 1. in gingival epithelia 2. in alveolar processes epithelia. 14 cases without sings of inflammation serve as control tissue. Total number of cases - 33. After informed consent had been obtained, simples of histological tissue specimens were collected on surgical extraction of the tooth. In the control group decision on the tooth extraction was taken for the orthodontic causes. Our data indicate that: 1. Heterogenity is typical to the oral cavity epithelium: a) Ultrastructural signs of keratinization and dissociation, with typical high activity of the terminal differentiation marker cytokeratin 10/13, predominate in the keratinocytes of gingival mucosa. b) Cells with signs of germination activity predominate in the ultrastructure of mucosa alveolar processes. Such cells express cytokeratin 14, typical to nonkeratinized epithelium. 2. Tissue architectonics as well as protein contents of cytoskeleton (judging by cytokeratine expression) are speared in the parodontal pathology in children, however in contrast to alveolar mucosa, damage to the microcirculatory vessels is more pronounced in gingival mucosa. 3. Expression of cytokeratines 10/13 and 14 may indicate the process of lysis and reparation of periodontal ligament.

The histological characteristics of cultured oral epithelium in different culture conditions

BACKGROUND

This study was undertaken to establish the characterization of cultured oral mucosal epithelium and introducing them as an alternative source for reconstruction of ocular surface disease.

METHODS

Human oral epithelial cells were cultured on simple media (DMEM/HF12) as control and co-cultured on mitomycin C-treated 3T3 feeder layer, on the amniotic membrane (AM) without nitrocellulose and the mitotically inactivated 3T3 fibroblast, and on the sandwich layer of AM fastened on the nitrocellulose as insert and 3T3 fibroblast. After 3 weeks, the characteristics of the cells were assessed morphologically and also ultrastructurally using scanning electron microscopy and transmission electron microscopy and immuno-cytochemically.

RESULTS

The epithelial cells were cultured on AM spread on nitrocellulose insert and 3T3 feeder layer showed better growth than other groups and all groups of study were shown similar characteristics. The cultured oral epithelial shared the characteristics with corneal epithelium.

CONCLUSION

Thus the oral epithelial could be an alternative source for transplantation.

The phenotype of persons having mosaicism for trisomy 21/Down syndrome reflects the percentage of trisomic cells present in different tissues

Little is known about the pathogenesis of the phenotype in individuals with trisomy 21 mosaicism and Down syndrome. The primary goal of this study was to identify factors contributing to the observed phenotypic variation by evaluating 107 individuals having trisomy 21 mosaicism. To investigate a potential "threshold" effect due to trisomic imbalance, lymphocyte and buccal mucosa nuclei were scored using FISH. Overall, buccal cells showed a significantly higher frequency of trisomy than lymphocytes (P < 0.0001). Using latent class analysis, two phenotypic classes were identified based on the clinical findings of the propositi. Patients from class 1 had significantly fewer traits and a lower percentage of trisomic cells (mean of 37.3% lymphocytes; 34.5% buccal mucosa cells) when compared to those stratified into class 2 (54.0% lymphocytes; 53.4% buccal mucosa cells). Tissue-specific influences were also detected, with buccal mucosa trisomy levels being significantly correlated with IQ (P = 0.0094; both ectodermal derivatives), while congenital heart defects were significantly correlated with lymphocytes (P = 0.0286; both mesodermal embryonic derivatives). In conclusion, allowing for the distinction of two groups, we observed variation in phenotype, associated with the percentage of trisomic cells. We also observed tissue-specific effects on phenotype. The results of this study should enable geneticists and other health care professionals to provide information regarding optimal diagnostic approaches and anticipated clinical outcomes.

DNA damage in lymphocytes and buccal mucosa cells of children with malignant tumours undergoing chemotherapy

The aim of the present study was to evaluate DNA damage (micronucleus) in cytokinesis-blocked lymphocytes and exfoliated buccal mucosa cells from children with malignant tumours and under chemotherapy. Micronucleated cells (MNCs) were assessed from children before and during chemotherapy. A total of 21 healthy children (controls), matched for gender and age, were used as control. The results pointed out higher frequencies of micronucleated lymphocytes in children with malignant tumour before any therapy when compared to healthy probands. Furthermore an increase of micronucleated lymphocytes during chemotherapy was detected when compared to the data obtained before chemotherapy. No statistically significant increases of MNCs were noticed in buccal mucosa cells at any of the timepoints evaluated. Taken together, these data indicate that the presence of malignant tumours may increase the frequency of DNA damage in circulating lymphocytes, these cells being more sensitive for detecting chromosome aberrations caused by anti-cancer drugs.

Analysis of lymphocyte and oral mucosa cell micronuclei in Cuban paint industry workers

Twenty-one workers exposed to complex mixtures in the paint industry were compared with a control group of 19 persons from a blood bank in regard to micronuclei frequency in peripheral blood lymphocytes and in oral mucosa cells. The exposed persons showed significantly increased levels of micronuclei frequencies in both types of cells.

Parallel frequency-domain optical coherence tomography scatter-mode imaging of the hamster cheek pouch using a thermal light source

We use a parallel frequency-domain optical coherence tomography (FDOCT) system to generate a scatter-mode image of the hamster cheek pouch epithelium. To our knowledge, this is the first optical coherence tomography (OCT) image of a biological sample obtained using a thermal light source in the frequency domain. The system employs an imaging spectrometer to acquire depth-resolved profiles from adjacent spatial points without the need for any scanning. To enable this imaging modality, we have considered that signals originating from multiple depths combine in a different manner in FDOCT compared to time-domain optical coherence tomography (TDOCT). Because a multicomponent FDOCT signal is a coherent sum, it is necessary to limit the number of modes that contribute to the detected signal. Conversely, multicomponent TDOCT signals can be represented as incoherent sums, where increasing the number of modes improves the signal.

Regional odontodysplasia: morphological, ultrastructural, and immunohistochemical features of the affected teeth, connective tissue, and odontogenic remnants

PURPOSE

Regional odontodysplasia (RO) is a rare developmental odontogenic defect. The affected teeth are described as "ghost teeth," due to malformation of dentin, enamel, and cementum. The purpose of this study was to describe the ultrastructural characteristics of the affected teeth as well as the immunohistochemical features of the soft tissue associated with 2 cases of regional odontodysplasia.

METHODS

Two cases diagnosed as RO were included on the study. After diagnosis, affected teeth and associated soft tissue were surgically removed from both patients and processed for light and scanning electron microscopy (SEM) analysis. For light microscopy, the specimens were decalcified in 5% nitric acid for 10 to 16 days and stained with hematoxylin and eosin. For SEM studies, specimens were cleaned with diamond paste and, after polishing, treated with 37% phosphoric acid for 5 minutes and covered by a thin layer of metallic gold. Soft tissues covering and surrounding the extracted teeth were routinely processed, and submitted to immunohistochemical reactions against pan-cytokeratins, cytokeratin 19, vimentin, laminin and collagen IV.

RESULTS

Both enamel and dentin showed gross alterations, including hypomineralization and discoloration, being more prominent on the coronal structures than the radicular structures. Ultrastructural features included alterations on the prismatic enamel surface, dentinal grooves, interglobular dentin, and hypoplastic and hypocalcified dental hard tissues. The soft gingival and alveolar tissue surrounding and covering the affected teeth showed calcifications and odontogenic remnants, positive for cytokeratin 19, laminin, and collagen IV.

CONCLUSIONS

Enamel and dentin are grossly altered in regional odontodysplasia, while cementum is less affected, and soft-tissue calcifications are associated with odontogenic cytokeratin-positive epithelial remnants, in addition to mesenchymal components.

SEM analysis of oral lichen planus before and after treatment with 13 cis-retinoic acid

Cancer of the oral cavity is a frequent worldwide neoplasia, averaging 4% in men and 2% in women. Cancer of the oral cavity is often preceded by particular epithelial lesions, called precancerous lesions. The aim of this study is to evaluate, by SEM microscope analysis, before and after treatment with 0.1% 13-cis-retinoic, the morphostructural variation of the surface of the oral mucous affected by lichen planus in respect to healthy oral mucous. Following topical therapy with 0.1% 13-cis-retinoic acid for 8 weeks, a restoration of the physiological morphostructure was observed by SEM, demonstrating the efficaciousness of the treatment and the SEM analysis for identifying the lesions of oral epithelium.

Differentiation of mucous membrane pemphigoid subgroups with confocal imaging

OBJECTIVE

Mucous membrane pemphigoid is an immune-mediated subepithelial blistering disease consisting of immunologically heterogeneous subgroups. Differentiation between these subgroups is important because they differ in prognosis. This study uses oral mucosal pemphigoid specimens to investigate the utility of computer-aided fluorescence overlay antigen mapping and laser scanning confocal microscopy to differentiate subgroups of mucous membrane pemphigoid.

STUDY DESIGN

Thirty oral mucosal biopsy specimens were cryosectioned and immunostained, although only 13 could be analyzed due to technical difficulties. In vivo bound antibodies and molecular markers of the basement membrane zone were differentially labeled with fluorescent antibodies. Fluorescent signals were imaged, and the spatial localization of in vivo bound antibodies was compared with the markers and analyzed.

RESULTS

In vivo bound IgG antibodies colocalized with beta4-integrin in 3 cases, with laminin-5 in 8 cases, and with collagen VII in 2 cases.

CONCLUSION

Fluorescence overlay antigen mapping and laser scanning confocal microscopy are useful techniques to differentiate pemphigoid subgroups in oral biopsy specimens.

Histological and histochemical evaluation of human oral mucosa constructs developed by tissue engineering

Reconstruction of large oral mucosa defects is often challenging, since the shortage of healthy oral mucosa to replace the excised tissues is very common. In this context, tissue engineering techniques may provide a source of autologous tissues available for transplant in these patients. In this work, we developed a new model of artificial oral mucosa generated by tissue engineering using a fibrin-agarose scaffold. For that purpose, we generated primary cultures of human oral mucosa fibroblasts and keratinocytes from small biopsies of normal oral mucosa using enzymatic treatments. Then we determined the viability of the cultured cells by electron probe quantitative X-ray microanalysis, and we demonstrated that most of the cells in the primary cultures were alive and had high K/Na ratios. Once cell viability was determined, we used the cultured fibroblasts and keratinocytes to develop an artificial oral mucosa construct by using a fibrin-agarose extracellular matrix and a sequential culture technique using porous culture inserts. Histological analysis of the artificial tissues showed high similarities with normal oral mucosa controls. The epithelium of the oral substitutes had several layers, with desmosomes and apical microvilli and microplicae. Both the controls and the oral mucosa substitutes showed high suprabasal expression of cytokeratin 13 and low expression of cytokeratin 10. All these results suggest that our model of oral mucosa using fibrin-agarose scaffolds show several similarities with native human oral mucosa.

Neurotized nevi of the oral mucosa: an immunohistochemical and ultrastructural analysis of nevic corpuscles

BACKGROUND

Nevic corpuscle (NC), a stacked lamellar structure reminiscent of Meissner corpuscle, is frequently observed in dermal melanocytic nevi. Although the heading 'neurotized' is classically used for these nevi, the exact neural nature of NC has been a topic of considerable debate. Neurotized nevi have received little attention in the dental literature, and there was no information on NC in oral melanocytic nevi.

METHODS

Six cases of oral intramucosal nevi with a significant number of NC (two completely and four partially neurotized nevi) were examined immunohistochemically and ultrastructurally.

RESULTS

NC was composed of closely piled laminar cells devoid of visible melanin. NC and associated spindle nevus cells were immunopositive for S-100 protein but negative for HMB-45, myelin basic protein and epithelial membrane antigen. Within NC, no reactivity for neurofilament protein, protein gene product 9.5 or peripherin was evident. Numerous CD34-positive dendritic cells were located between nevus cells and often encircled NC. Ultrastructurally, NC consisted of concentrically layered elongated cells with a slender lamellated cytoplasm rich in thin filaments and pinocytotic vesicles. Their cytoplasmic processes were focally covered by external basal lamina and continuous to spindle nevus cells. Occasional NC cells contained a few melanosomes. There was no interposed axon in NC.

CONCLUSIONS

Despite the close resemblance to Meissner corpuscle, NC showed no axonal supply. NC cells lacked terminal Schwannian differentiation and appeared to be modified melanocytes with some perineurial ultrastructural characteristics. The presence of CD34-positive cells, presumably corresponding to endoneurial fibroblasts, further supports an organizational relationship of NC and peripheral nerve sheath elements.

The defense architecture of the human periimplant mucosa: A histological study

STATEMENT OF PROBLEM

The primary function of the periodontal tissues, besides attaching the tooth to the jaw, is gingival protection; that is, to provide a seal against the contaminated environment of the oral cavity. Detailed data regarding protection of the periimplant mucosa in patients with transmucosal implants are lacking.

PURPOSE

The purpose of this histological study was to demonstrate the structural and ultrastructural features of the interface between transmucosal titanium implants with oxidized, machined, and acid-etched surfaces and surrounding tissues by combined light and electron microscopy.

MATERIAL AND METHODS

Five patients received 12 experimental titanium, 1-piece mini-implants with an oxidized, acid-etched, or machined surface distal to conventional implants. Following transmucosal healing of 8 weeks and at the abutment connection of the regular implants, the mini-implants were removed with a layer of surrounding hard and soft tissue. The specimens were fixed and processed for light, transmission electron, and scanning electron microscopy.

RESULTS

For all 3 types of surfaces, substantial structural analogies were demonstrated between gingiva and periimplant mucosa in humans, both shown to provide protection for the underlying soft tissues and alveolar bone. Depending on the implant surface texture, substantial differences were noted in the manner the implants interface with connective tissue.

CONCLUSIONS

The mechanisms of protection in the periimplant mucosa correspond to those in the gingiva surrounding a tooth. The surface texture of implants may affect the orientation of collagen fibers of the connective tissue at the implant surface.

Histological and ultrastructural aspects of the tongue in undernourished rats

There are few published studies on the effects of protein-caloric undernourishment on the oral mucosa.

Objectives

The objective of this study is to verify the histological and ultrastructural aspects of the tongue mucosa in protein-caloric undernourished adult rats.

Material and Methods

A clinical experimental study was done in thirty Wistar rats, 15 controls and 15 with protein-caloric undernourishment. The last group received ration in small amounts, with a reduced casein content, during 45 days. Rats were weighed every 3 days, from the first (90 days of life) to the last day of a 45-day dietary period, when they were sacrificed. Plasma was used for protein electrophoresis and their tongues were prepared for light and scanning electron microscopy. Analysus of variance and Student's t-test were used for statistical analysis.

Results

A significant decrease in weight and in plasma proteins was found in protein-caloric undernourished rats compared to the control group. Histological findings revealed no differences between the two groups and there were no statistically significant differences in the filiform papilla count under the scanning electron microscopy.

Conclusion

Protein-caloric undernourishment does not cause alterations in the tongue mucosa of adult rats.

Soft tissue healing at titanium implants coated with type I collagen. An experimental study in dogs

OBJECTIVE

To analyse the soft tissue healing at titanium implants coated with type 1 collagen.

MATERIAL AND METHODS

Six dogs were used. The mandibular pre-molars and the three anterior maxillary pre-molars were extracted. Three months later mucoperiosteal flaps were raised and two test and two control implants were installed (3i TG Osseotite 3.75 x 10 and 2.8 mm transmucosal collar). The test implants were coated with a purified porcine type I collagen. Cover screws were placed and flaps were sutured. The sutures were removed 2 weeks later and a plaque-control programme was initiated. Another 2 weeks later, the procedure was repeated in the contra-lateral mandibular region. Four weeks after the second implant surgery, biopsies were obtained and prepared for histological examination.

RESULTS/CONCLUSION

The vertical dimensions of the epithelial and connective tissue components as well as the composition of the connective tissue portion facing the implant were similar at collagen-coated and uncoated implants after 4 and 8 weeks of healing. It is suggested that soft tissue healing to implants coated with type I collagen was similar to that at non-coated titanium implants and that no adverse reactions to the collagen-coated implants occurred.

Epstein-Barr virus (EBV)-infected monocytes facilitate dissemination of EBV within the oral mucosal epithelium

Epstein-Barr virus (EBV) causes hairy leukoplakia (HL), a benign lesion of oral epithelium that occurs primarily in the setting of human immunodeficiency virus (HIV)-associated immunodeficiency. However, the mechanisms of EBV infection of oral epithelium are poorly understood. Analysis of HL tissues shows a small number of EBV-positive intraepithelial macrophages and dendritic/Langerhans cells. To investigate a role for these cells in spreading EBV to epithelial cells, we used tongue and buccal explants infected ex vivo with EBV. We showed that EBV first infects submucosal CD14(+) monocytes, which then migrate into the epithelium and spread virus to oral epithelial cells, initiating productive viral infection within the terminally differentiated spinosum and granulosum layers. Incubation of EBV-infected monocytes and oral explants with antibodies to CCR2 receptor and monocyte chemotactic protein 1 prevented entry of monocytes into the epithelium and inhibited EBV infection of keratinocytes. B lymphocytes played little part in the spread of EBV to keratinocytes in our explant model. However, cocultivation of EBV-infected B lymphocytes with uninfected monocytes in vitro showed that EBV may spread from B lymphocytes to monocytes. Circulating EBV-positive monocytes were detected in most HIV-infected individuals, consistent with a model in which EBV may be spread from B lymphocytes to monocytes, which then enter the epithelium and initiate productive viral infection of keratinocytes.

Junctional basement membrane anomalies of skin and mucosa in lipoid proteinosis (hyalinosis cutis et mucosae)

BACKGROUND

Excessive basement membrane (BM) deposition in skin and mucosa is characteristic for lipoid proteinosis (LP; hyalinosis cutis et mucosae), an inherited disease caused by extracellular matrix protein 1 (ECM1) mutations. According to ultrastructure there are striking differences between junctional and microvascular BM.

OBJECTIVE

Distinct analysis of the junctional zone in epidermis and oral mucosa, contrasting concentric BM arrays in the microvasculature; evaluation of impact on epithelial histogenesis and differentiation, and specifically on adhesion structures to BM (hemidesmosomes).

METHODS

LP-epithelia were analyzed for alterations in differentiation, BM composition and texture, and hemidesmosomal components by indirect immunofluorescence (IIF), electron microscopy (EM), and immunoelectron microscopy (ImEM).

RESULTS

Most striking was the irregular deposition of collagen IV and VII, BM-laminin, and laminin-5 at the junctional zone, accompanied by lamellate or punctuated structures below BM (IIF), whereas integrin alpha6beta4 and bullous pemphigoid antigen-1 and -2 (BPAG-1/-2) were regularly aligned. Also integrins alpha2beta1 and alpha3beta1 remained restricted to the epidermal basal layer, while the tissue-specific differentiation markers keratin K1/10 (mucosa, additionally K4/13) appeared delayed indicating mild hyperplasia, further confirmed by focal K6/16 expression. Ultrastructure (EM) disclosed abundance of extended basal cell protrusions and junctional aberrations like exfoliating excessive BM material. Hemidesmosomes were complete, but ImEM indicated weakened interactions between their components (BPAG-1, -2, and HD1). Confirming IIF, collagen IV and VII, and laminin-5 appeared extensively scattered, the latter two probably remaining associated.

CONCLUSIONS

Subtle defects in anchorage assembly, spanning the entire BM zone, apparently compromise epithelial-matrix adhesion, which may provoke (mechanical stress-induced) erroneous BM repair.

Structural reactions of the buccal mucosa in diabetic parodontopathy

Pronounced changes in the capillaries, hemodynamic disorders, epitheliocyte degeneration and atrophy develop in the buccal mucosa of patients with types I and II diabetes mellitus in the absence of inflammatory cellular infiltration or with facultative infiltration. The morphogenesis of pathological changes can be regarded as primary diabetic microangiopathy causing metabolic disorders with the development of degenerative and atrophic changes in all structural components of the buccal mucosa and development of diabetic parodontopathy, a primary degenerative process.