bluuebunny/crossref_metadata_2025 huggingface dataset:
Calcification patterns of rat condylar cartilage after induced unilateral malocclusion
Authors: Ehrlich J. , Bab I. , Yaffe A. , Sela J.
Published: April 2006

Occlusal interferences on right upper molars in rats produced ultrastructural changes in the calcification of ipsilateral condylar cartilage. This was characterized by premature appearance of apatite crystals within extracellular matrix vesicles present in the proliferative cell zone. The normal proliferative cell zone in the rat condyle manifested noncalcifying vesicles. The zone of calcification in rats with an occlusal splint revealed longitudinal calcifying fronts in the vicinity of the chondrocytes. These fronts were composed of haphazardly distributed apatite crystals. These ultrastructural alterations support the generally accepted view that mechanical stimuli induce changes in the process of primary mineralization.
Tumor antigens in neoplasms of the human parotid gland
Authors: Caselitz J. , Seifert G. , Jaup T.
Published: April 2006

In a collection of parotid gland tumors the presence of different antigens was studied by immuno‐histochemical methods. The series was composed of different tumors: adeno‐ and cystadenocarcinomas, adenoid‐cystic carcinomas, salivary duct carcinomas, mucoepidermoid tumors, squamous cell carcinomas and anaplastic carcinomas.

The following substances were studied:

Substances normally present in salivary glands like lysozyme and lactoferrin.

Oncofetal antigens: earcinoembryonic antigen (CEA) and alpha‐feloprotcin (AFP).

Different classes of intermediate‐sized filaments: prekeratin and vimentin. The presence of lactoferrin and carcinoembryonic antigen could be demonstrated in the glandular differentiated tumors, whereas the squamous cell carcinomas, although CEA positive, were lactoferrin negative. The anaplastic carcinomas were negative for lactoferrin and CEA. Lysozyme and AFP could not be demonstrated in the tumors of our material.

Mucoepidermoid tumors and squamous cell carcinomas were clearly positive for prekeratin filaments whereas the stromal part showed vimentin filaments in the cytoplasm of fibroblasls. These antigens provide a useful tool to distinguish between the epithelial and mesenchymal tumors.
A clinical, histomorphological and histochemical study on snuff‐induced lesions of varying severity
Authors: Hirsch Jan‐Michaél , Heyden Guy , Thilander Holger
Published: April 2006

The oral lesions in 50 habitual snuff‐dippers were graded on a four‐point scale. The patients' tobacco and drinking habits were studied by means of a questionnaire. From each patient a biopsy was taken for histomorphological and histochemical analysis. A correlation between snuff habits and the clinical degrees was found, as well as between the snuff habits and certain superficial and deeply located cell changes. The incidence of keralinized lesions, sialadenitis and slight dysplasia (based on subjective evaluation under a light microscope) was higher than previously reported. Presence of dysplastic changes could not be predicted by means of the parameters which characterise the snuff habit or from the clinical grade. The histomorphological and histochemical results were interpreted as showing that the mucosa react to snuff inducing hyperplasia in the basal cell layers. In the surface layer indications of lethal damage were found. The overall stromal reaction to snuff was weak. However, the salivary glands and excretory ducts exhibited degenerative changes which were found to be more severe than the pathological changes in the surface epithelium.
Calcifying epithelial odontogenic tumors:
Authors: Ai‐Ru Liu , Zhen Liu , Jian Shao
Published: April 2006

Nine cases of CEOT are reported. There are seven intra‐osseous and two extra‐osseous tumors. All but one occurred in the mandible. The age range was 20 to 64 years; averaging 34.2 years. There were 7 females and 2 males. Radiographically, they appeared either as monocystic or polycystic translucent lesions with radiopaque spots or masses. Embedded teeth were seen in six cases. Microscopically, four different patterns are described. No recurrence has been found post‐operatively within 2–14 years of follow‐up study.

The nature of the reddish homogeneous material, the histogenesis of the tumor and the treatment are briefly discussed.
Etiology of oral squamous cell carcinoma
Authors: Binnie W. H. , Rankin K. V. , Mackenzie I. C.
Published: April 2006

The traditional list of etiological factors related to oral squamous cell carcinoma namely, tobacco, alcohol, syphilis, and oral sepsis has been expanded to include iron deficiency, chronic candidosis, and herpes simplex virus. The development of current concepts in these areas is discussed. In evaluating the need for future research, special emphasis is given to the concepts of multifactorial etiology and the role of mutagens. Suggestions for future research are discussed.
Ameloblastic fibroma with dentinoid formation/immature dentinoma
Authors: van Wyk C. W. , van der Vyver P. C.
Published: April 2006

The epithelial‐connective tissue interface in an ameloblastic fibroma with dentinoid formation shows four characteristic features: epithelium which is surrounded by a cellular stroma, by a cell‐free zone, by a cell‐free zone consisting of an amorphous hyaline‐like material, and by a dentinoid material. The ultrastructure of these four characteristics resembles stages of the developing tooth. The cellular epithelial‐connective tissue interface corresponds to early development before the “bud cap” stage described by Sisca and Provenza (1972). The cell‐free zone resembles the “bud cap” stage, and the amorphous layer the “intermediate bell” stage, whereas the interface with dentinoid material has all the features of the “late bell” stage, except for the absence of calcification.
Distribution of ABO blood group substances in various types of oral lichen planus
Authors: Thomopoulou‐Doukoudakis A. , Squier C. A. , Hill M. W.
Published: April 2006

Formalin‐fixed, paraffin‐embedded tissue sections of fifty oral lichen planus lesions including hypertrophic, atrophic and erosive types, were examined by an immunofluorescent technique for the presence of the ABO blood group antigens. The antigen activity in lichen planus lesions was compared with the reactivity of normal human and Rhesus monkey oral mucosa as controls, and the reactivity of adjacent normal epithelium in the same specimen. A difference in the distribution of the blood group substances was observed in the three different types of oral lichen planus. The hypertrophic showed the strongest staining reaction approaching that of the normal, whereas a decrease in quantity of blood group substances was seen in the atrophic, and a tendency to complete loss in the erosive type. There was a marked tendency for loss of staining to be greater in lesions from older patients; this could be related to the greater frequency of atrophic and erosive lesions in the elderly.
Epidermolysis bullosa
Authors: Wright J. T. , Gantt D. G.
Published: April 2006

Epidermolysis bullosa (EB) describes a group of rare genetic mechanico‐bullous disorders. The disease has several modes of inheritance with various degrees of severity and expression. Two cases of recessive dystrophic EB are presented which show typical cutaneous, mucosal and occular involvement.

The teeth were severely affected in both cases with much of the coronal enamel absent upon emergence into the oral cavity. The cervical enamel showed occasional hypoplastic pits. In one case, there was taurodontism of the permanent first molars. This case illustrates the increased occurrence of taurodontism associated with diseases affecting tissues of ectodermal origin. Taurodontism has not been previously reported with EB. Histologic studies of the teeth using light microscopy (LM) and scanning electron microscopy (SEM) revealed that the cementum and dentin were normal. The enamel, under LM, showed a prismatic structure with a broad neonatal line. SEM showed a wide amorphous zone of enamel adjacent to the dentin. Generalized throughout the enamel were globular areas within the prisms, which appeared to be local deformations. Hypoplastic pits on the surface were round and of varying diameters. The affected teeth exhibited both hypomaturation and hypo‐plastic defects of the enamel.
Carboxylic acids and pH of denture plaque in patients with denture stomatitis
Authors: Samaranayake L. P. , Weetman D. A. , Geddes D. A. M. , MacFarlane T. W.
Published: April 2006

Denture stomatitis (DS) is the commonest form of oral Candida infection. Although it has been suggested that the acidic conditions prevailing beneath maxillary dentures may potentiate palatal inflammation associated with DS, little is known about the pH and carboxylic acids of denture plaque in subjects with and without the disease. Therefore, qualitative and quantitative analyses of short‐chain carboxylic acids and pH of maxillary denture plaque of ten patients and nine controls were performed. Gram‐stained smears of plaque revealed numerous yeasts in the DS plaque while yeasts were absent in control plaque. Acetate, lactate, propionate, succinate, formate and pyruvate were present in descending order of concentration in all plaque samples. DS plaque was more acidic and contained significantly lower concentrations of lactate ions than control plaque. These results imply that the carboxylic acids produced by the microflora of denture plaque may be aetiologically involved in the pathogenesis of denture stomatitis.
Prediction of malignant change in oral precancerous lesions by DNA cytofluorometry
Authors: Saku Takashi , Sato Eiichi
Published: April 2006

In order to investigate the possibility of predicting malignant transformation of oral precancerous lesions in the initial biopsy specimens, Feulgen‐DNA cytofluorometry was applied to the initial biopsies of 7 cases of leukoplakia and one of lichen planus which later showed malignant transformation, using smears of squamous epithelial cells isolated from thick paraffin sections with non‐specific fluorescence blocking. Analysis of DNA ploidy patterns revealed that “dysplastic changes” of DNA histograms in cases with epithelial dysplasia tended to be expressed by a shift of the modal peak to hyperdiploid values and by an increased number of cells in 2.5 C to 3.5 C and hyper‐4 C, regardless of the prognosis. However, in the cases with subsequent malignant transformation, the DNA histogram was characterized by the appearance of bimodal peaks.
Oral lichen planus: characterization of immunocompetent cells with hybridoma antibodies
Authors: Becker J. , Löning Th. , Reichart P. , Hartmann N.
Published: April 2006

Monoclonal antibodies which react against T‐cell subpopulations and Langerhans' cells were used to examine the phenotype of immunocompetent cells in oral lichen planus. Immunomorphologically, the stromal infiltrate of this condition considerably resembled the delayed type of immune reaction. Although all subpopulations of immunocompetent cells were present in the stromal infiltrate, Langerhans' cells (OKT‐6 positive, HLA‐DR positive) and suppressor/cytotoxic T‐lymphocytes (OKT‐3 positive, OKT‐4 negative, OKT‐8 positive, HLA‐DR positive) predominated. Our immunohistological findings support the suggestion that aggregations of T‐lymphocytes are responsible for the cytotoxic processes which occur within the squamous epithelium in oral lichen planus.
Extramedullary plasmacytoma associated with a Castleman's lesion of the cervical nodes
Authors: Kurihara K. , Hashimoto N.
Published: April 2006

A rare case of extramedullary plasmacytoma seen in a patient with a Castleman's lesion is described. The mass occurred in the cervical nodes of a 61‐year‐old female patient, and the primary site was the intra‐ or peri‐parotid nodes. The histological examination revealed abnormal characteristic lymph follicles and nodular proliferation of plasma cells in the same lymph nodes. The neoplastic change of plasma cells was studied on the basis of the immunoperoxidase (PAP) method. The patient is well without recurrence 15 months after total resection.
Cytoplasmic granules in exfoliated buccal epithelial cells
Authors: van Wyk C. W. , van der Vyver P. C.
Published: April 2006

The cytoplasmic granules in exfoliated epithelial cells of healthy cheek mucosae of seven subjects were studied by means of phase‐contrast microscopy, electron microscopy and histochemistry. An electron microscopic technique was used to study specific granules which had been identified with the light microscope. Phase‐contrast microscopy revealed that the cytoplasmic granules are present in unfixed material. Ultrastructurally they consist mostly of discrete, dense granular bodies. Also seen were collections of electron‐dense masses, collections of organelles and organelles mixed with granular bodies and electron‐dense masses. Histochemically they stain like keratohyalin. No lipids were detected. We propose that the discrete bodies are normal keratohyalin granules and the electron‐dense masses are granules in stages of disintegration. When the granules break down they become mixed with organelles. The keratohyalin granules are the darkly‐stained granules seen microscopically, and the disintegrating granules and collections of organelles the weakly‐stained, indistinct cytoplasmic granules.
Effect of long‐term application of snuff on the oral mucosa: an experimental study in the rat
Authors: Hirsch J.‐M. , Johansson S. L.
Published: April 2006

The long‐term effect of snuff exposure was studied in Sprague‐Dawley rats using a surgically‐created test canal in the lower lip to retain snuff. The rats received standard snuff (n = 42) and highly alkaline snuff (n = 10) for 9–22 months, whereupon they were killed. Untreated rats with identical test canals (n = 15) served as controls. A complete post‐mortem examination was performed. One rat exposed to standard snuff for 9 months developed a squamous cell carcinoma of the oral cavity. However, exposure to standard snuff usually resulted in a mild to moderate hyperplasia of the epithelium, hyperorthokeratosis and acanthosis. Rats exposed to snuff for 18–22 months showed vacuolated cells penetrating deeper into the epithelium with hyperplastic and atrophic lesions. In a few rats, severe dysplastic changes developed in the crevicular epithelium. Rats exposed to alkaline snuff differed little from the first group except that there was focally atrophic and ulcerated epithelium and less fibrosis. Pathological findings outside the oral cavity were rare. Squamous cell hyperplasia of the forestomach was found in rats exposed to snuff for 18–22 months, possibly caused by ingested snuff. In conclusion, this study has shown that exposure of rats to snuff for 10–16 hours per day 5 days a week for most of their life‐span resulted in lesions mainly restricted to the epithelium and the underlying connective tissue of the surgically created test canal.
Use of x‐ray microanalysis to monitor diffusion of Zn from a cement into human dentin
Authors: Ashrafi S. H. , Waterhouse J. P. , Baratieri A. , Picarelli A. , Somma F. , Patel M.
Published: April 2006

Energy dispersive x‐ray spectrometry (EDAX system), with scanning electron microscopy was used to detect diffusion of Zn from a source in human dentin and the system was tested for sensitivity and reproducibility. Sections of human teeth in which a ZnO‐eugenol cement had been placed in a cavity in the dentin in vivo were prepared and x‐ray microanalytical measurements carried out. We found that values of counts for Zn, Ca and P in the same field were linear up to a total counting time of 60 sec. We further found that reproducibility of values between repeat examinations of the same specimens on different days was excellent. The concentration of Zn in the dentin decreased exponentially with distance from source within the distance tested. We conclude that the system can be used to detect trace concentrations of Zn, and that accordingly the diffusion behavior of a variety of ions in dentin could be monitored.
The effect of DMBA on hamster cheek pouch mucosa in vitro: constant exposure
Authors: Mock D. , Main J. H. P. , Delgado Fdez R.
Published: April 2006

Repeated topical application of DMBA to hamster cheek pouch mucosa in vivo has been shown to cause dysplastic changes and ultimately the development of squamous cell carcinomas in the epithelium. A technique has already been reported whereby neonatal hamster pouch mucosa can be maintained in vitro and dysplastic changes have been described in the epithelium after a single exposure to DMBA. By 35 days in organ culture, these changes disappeared and the epithelium regained its normal organotypic morphology. In this study, the tissue was maintained in vitro in medium containing various concentrations of DMBA for up to 49 days. Dysplastic changes were seen in the epithelium of the explants with some histological evidence of malignant behaviour. These changes were observed throughout the experimental period.
An enzyme histochemical study of human salivary duct calculi
Authors: Isacsson G. , Hammarström L.
Published: April 2006

An investigation was undertaken to study the distribution of enzymes associated with submandibular gland salivary calculi. Ten calculi were freeze‐sectioned and incubated for acid and alkaline phosphatases and for lactate, succinate and maleate dehydrogenases. All calculi were partly covered by a 50–210 μm wide zone of organic material consisting of connective tissue and metaplastic squamous epithelium facing the mineralized calculus, or of a structureless substance attached to the mineralized calculus. The epithelium showed an intense staining reaction for acid phosphatase and lactate dehydrogenase and a moderate reaction for succinate dehydrogenase throughout all levels of the epithelium. The structureless peripheral zone exhibited a moderate activity of acid phosphatase and succinate dehydrogenase located to an area close to the mineralized matrix. Also alkaline phosphatase and lactate dehydrogenase were found in a special pattern in the structureless zone. Sodium fluoride and sodium vanadate added to the incubation medium inhibited acid phosphatase activity whereas cupric chloride only lowered the staining reaction. Enzyme activity was found only within the peripheral zone of organic material with one exception. The results suggest that the calcification process of salivary calculi is not a passive calcification of necrotic material or mucin but rather an active process promoted by enzymes in the surrounding organic substances.
The origin of osteoclasts:
Authors: Marks S. C.
Published: April 2006

Recent evidence for an extraskeletal origin of osteoclasts and the historical record of the genesis of osteoclasts are examined critically. Reviews of the structure, function and development of osteoclasts from mononuclear precursors, the local regulation of bone resorption and the coupling of bone formation to preceding resorption are presented as a background for discussing the clinical implications for management of osteolytic bone diseases. The roles of osteoclasts and macrophages as phagocytes are compared and contrasted, and recent evidence for macrophage heterogeneity resulting from site‐specific monoblastic precursors is reviewed. The implications of these recent developments in macrophage biology are extrapolated to osteoclasts and the existence of site‐specific, extraskeletal tsteoclast precursors is proposed. Finally, the investigative challenges inherent in these perspectives are discussed.
The detection and prevalence of reactive and physiologic sclerotic dentin, reparative dentin and dead tracts beneath various types of dental lesions according to tooth surface and age
Authors: Stanley H. R. , Pereira J. C. , Spiegel E. , Broom C. , Schultz M.
Published: April 2006

The pulpo‐dentinal complex responds to external injuries with dentin sclerosis (DS), dead tracts (DT), or reparative dentin (RD). This investigation correlates the prevalence of these responses with age, sex, type and surface location of tooth lesions (caries, restorations, attrition, abrasion and erosion) utilizing ground sections, microradiographs and decalcified paraffin‐embedded tooth sections treated with the Pollak trichome stains (270 teeth from 113 patients). The main response to caries, restorations and erosion was DS, followed by RD and DT. DS, RD and DT occurred equally in any tooth, on any tooth surface and even beneath the same lesion. DS did not necessarily prevent RD. Root and furcation DS and RD in the floor of the pulp chamber and root canals were unrelated to particular lesions but did relate to increasing age. Root DS extended from apical to cervical area with increasing age. Beneath caries and restorations DS and RD were more prevalent in males, but DT was more prevalent in females. Pollak staining of decalcified paraffin sections for DS was approximately 80% as accurate as ground sections and micro‐radiography. In pulp studies, where the result is contrary to previous experience, the Pollak stains reveal whether DS has decreased dentin permeability.
Sequential histological changes and mast cell response in skin during chemically‐induced carcinogenesis
Authors: Farnoush A. , Mackenzie I. C.
Published: April 2006

Skin tumors experimentally induced by dimethylbenzathracene (DMBA) are associated with dense subepithelial accumulations of mast cells. To investigate the sequential changes of the mast cell population during carcinogenesis, and to provide a model with which to examine mast cell proliferation, the back skin of 48 Swiss Webster mice was painted with 0.5% DMBA in benzene twice weekly for 12 weeks. Control and DMBA‐treated tissues were processed for histological examination. The observed pattern of tissue changes fell into four phases: a) inflammation and necrosis followed by epithelial regeneration and hyperplasia, b) development of localized regions of acanthosis, c) loss of normal organization with downgrowth of epithelial cells and formation of keratin pearls, d) appearance of well‐defined nodules resembling verrucous carcinoma. Subepithelial mast cells varied greatly in number during the above sequence of changes. Dense foci of cells were seen, particularly beneath the regions of hyperplastic epithelium. Mast cells may play a role in abnormal epithelial proliferation and, further, DMBA treatment may provide a suitable model with which to examine the origin and kinetics of mast cells.
Remineralization of softened human enamel in mucin‐ or CMC‐containing artificial salivas
Authors: Gelhard T. B. F. M. , Fidler V. , 's‐Gravenmade E. J. , Vissink A.
Published: April 2006

The rehardening properties of four saliva substitutes on artificially softened human enamel have been investigated by microhardness measurements. The saliva substitutes were all based on the same formula, containing calcium, phosphate and fluoride as the main electrolytes, and mucin or carboxymethylcellulose as the main macromolecules. It has been shown that a rehardening potential exists in the saliva substitutes when calcium and phosphate are present. Omitting F− greatly reduces the rehardening potential. The rehardening is better in case of the CMC‐containing saliva than in that containing mucin.
Effects of repeated treatment of hamster ear epidermis and cheek‐pouch mucosa with 12‐0‐tetradecanoylphorbol‐13‐acetate
Authors: Harris R. R. , Mackenzie I. C.
Published: April 2006

The effects of repeated stimulation of hamster oral mucosa and epidermis with 12‐0‐tetradecanoylphorbol‐13‐acetate (TPA), were examined using in vitro assays of glycolysis and amino acid incorporation. The response of control and hyperplastic tissues to epinephrine and cAMP, and their rates of incorporation of histidine and leucine, were also examined. Repeated treatment with TPA in the concentration range of 1 × 10−8 to 1 × 10−5 M resulted in increased rates of glycolysis, amino acid incorporation and mitosis in both tissues. During the induction of hyperplasia, a loss of the normal epithelial response to epinephrine was observed at Day 8, suggesting re‐establishment of mechanisms controlling homeostasis. Application of TPA resulted in a reduction in the amount of histidine incorporated relative to leucine.
Protein synthesis in vitro, in the presence of Ca(OH)2‐containing pulp‐capping medicaments
Authors: Hanks C. T. , Bergenholtz G. , Kim J.‐S.
Published: April 2006

Four Ca(OH)2‐containing pulp‐capping medicaments were compared for their effects on protein synthesis in early subcultures of monkey‐ and human‐pulpal fibroblasts. While protein synthesis, as well as DNA synthesis, was depressed by three of the medicaments, the protein‐synthetic rate in human‐cell cultures in the presence of Life® rose to control levels when the medium was changed daily, but was depressed when the medium was not changed. This suggests that serum proteins play a protective role for pulpal tissues under inflammatory conditions, at least in the case of Life®, allowing odontoblasts to differentiate and make dentinal matrix without interference of either toxic components or excess alkalinity.
The nature of the amyloid‐like material in a calcifying epithelial odontogenic tumour: an ultrastructural study
Authors: El‐Labban N. G. , Lee K. W. , Kramer I. R. H. , Harris M.
Published: April 2006

An ultrastructural study was carried out to investigate the nature of an eosinophilic material, having the staining properties of amyloid, in a case of calcifying epithelial odontogenic tumour. At the electron‐microscopical level, the eosinophilic masses consisted of two types of structure which are probably related. The first type appeared as sheets of fine filaments measuring 10–12 nm in diameter. The second type was in the form of aggregates of lamina densa fragments, probably secreted by the tumour epithelium. These fragments appeared to undergo some loss of electron density and became degraded into fine filaments, having similar thickness and electron density to those forming the filamentous masses. It is concluded from this study that the fine filamentous material is a form of amyloid which results from degradation of lamina densa material.
Development of dinitrochlorobenzene contact hypersensitivity in rat submaxillary salivary gland
Authors: Mohammad A. R.
Published: April 2006

Stimulation of cell‐mediated immunity (CMI) by 2,4 dinitrochlorobenzene (DNCB) was reported to be effective in clinical regression of some carcinonas and precancerous lesions. This study investigated development of CMI in rat submaxillary salivary glands with dermal application of DNCB to provide a model for the sudy of immunotherapy in salivary gland neoplasia. Twenty rats received 0.02 ml of 0.5% DNCB in 4:1 acetone corn‐oil applied with a glass rod to 3 cm2 of clipped ventral skin of the neck covering the submaxillary salivary gland on 2 successive days. Ten days later, the submaxillary glands were challenged with an injection of 0.02 ml of DNCB. Thirty‐two h later the animals were killed and the glands examined grossly and microscopically. Thirty control animals were sensitized and challenged, (a) 10 with 0.5% DNCB, then vehicle only, (b) 10 with vehicle only, then 0.5% DNCB, and (c) 10 with vehicle both times. Gross examination of experimental and control glands disclosed moderate edema and congestion. Microscopically, experimental glands showed inflammatory changes including infiltration, vascular congestion and perivascular cuffing of lymphocytes. Regional lymph nodes showed proliferation of cortical germinal centers only. Control glands showed acute vascular congestion in group (a), and absence of microscopic features of delayed hypersensitivity.
Rheological properties of saliva substitutes containing mucin, carboxymethylcellulose or polyethylenoxide
Authors: Vissink A. , Waterman H. A. , 's‐Gravenmade E. J. , Panders A. K. , Vermey A.
Published: April 2006

Apparent viscosities at different shear rates were measured for 3 types of saliva substitutes: (a) mucin‐containing saliva; (b) substitutes based upon carboxymethylcellulose (CMC), and (c) solution of polyethylenoxide (PEO). The apparent viscosities were compared with those of human whole saliva. Human whole saliva and mucin‐containing saliva substitutes appeared to be similar in their rheological properties. Both types of solution are viscoelastic solutions and adjust their apparent viscosities to their biological functions. Preparations containing CMC or PEO are non‐Newtonian liquids. From this study it is concluded that mucin‐containing saliva substitutes appear to be the best substitutes for natural saliva, as far as rheological properties are concerned.
Effect of snuff and herpes simplex virus‐1 on rat oral mucosa: possible associations with the development of squamous cell carcinoma
Authors: Hirsch J.‐M. , Johansson S. L. , Vahlne A.
Published: April 2006

The purpose of this investigation was to study the effect of snuff and experimentally induced herpes simplex virus type 1 (HSV‐1) infection in Sprague‐Dawley rats. It was demonstrated that it was possible to obtain 100% development of acute HSV‐1 infection in the rat oral mucosa, but only 10% of latent reactive infection of the trigeminal ganglia. The rats were, therefore, acutely infected monthly with virus to simulate recurrence of latent infection. Virus was applied topically to the mucous membrane twice with an interval of one month. Snuff was administered between the virus applications and afterwards to half the virus‐exposed animals. Sham‐infected rats were given snuff during the same period (18 months). A fourth group of rats were left untreated. A complete post‐mortem examination was performed. Two rats exposed to snuff and HSV‐1 in combination developed squamous cell carcinoma of the oral cavity. It was also found that rats exposed to snuff alone or in combination with HSV‐1 had a higher incidence of tumours or tumour‐like conditions than control rats exposed to HSV‐1 only. The incidence of malignant tumours was significantly higher in rats exposed to snuff or HSV‐1 and snuff in combination than in control animals (p < 0.05). The results of the study indicate that HSV‐1 in combination with snuff exposure may be associated with the development of squamous cell carcinomas of the oral cavity.
Distribution of keratin and laminin in ameloblastoma. Comparison with developing tooth and epidermoid carcinoma
Authors: Thesleff I. , Ekblom P.
Published: April 2006

The nature of the tumor cells in 5 eases of ameloblastomas was studied by immunohistochemistry, and the findings were compared with developing mouse and human teeth as well as with 5 cases of carcinomas in the oral region. The antigens investigated were keratin, an intracellular cytoskeletal protein typical of epithelial cells, and laminin, an extracellular matrix protein found in basement membranes. Our results show that keratin is expressed by all types of epithelial cells in ameloblastomas as well as in the epidermoid carcinomas, and developing teeth. The epithelial, keratin‐positive tumor islands in the ameloblastomas were surrounded by a continuous line of laminin, in a pattern similar to that seen in developing tooth. Laminin was seen also around the epidermoid carcinomas but large areas devoid of laminin were constantly seen between the stroma and the neoplastic epithelium. This indicates a lack of proper basement membrane formation by the malignant epidermoid carcinomas. This may be due either to a diminished production or an increased degradation of basement membrane proteins by the carcinoma cells. Our results are in line with suggestions that ameloblastomas are derived from odontogenic epithelial cells. Immunostaining for keratin does not distinguish between carcinomas and the ameloblastomas. However, visualization of basement membrane proteins such as laminin can apparently be used in the differential diagnosis between ameloblastomas and carcinomas.
Immunohistochemical distribution of immunoglobulins, lactoferrin, and lysozyme in human minor salivary glands
Authors: Moro I. , Umemura S. , Crago S. S. , Mestecky J.
Published: April 2006

The immunoflorescence technique was used to examine the distribution of immunoglobulin A and its subclasses, secretory component (SC), J chain, lactoferrin and lysozyme in labial and lingual (von Ebner's) glands. IgA‐containing plasma cells were found in the connective tissue around intercalated or intralobular duels and a few were noted around acini of both glands. IgA was detected in the apical cytoplasm of intercalated and intralobular duct cells and in acini of von Ebner's glands and in demilunes of labial glands. Most IgA‐containing cells also stained for J chain. The ratio of IgA1:IgA2‐containing cells was approximately equal in von Ebner's and labial glands. Cytoplasmic and surface membrane‐related staining for SC was detected in epithelial cells of the intercalated and intralobular ducts in both glands, in the serous acini of von Ebner's gland, and in the demilunes of labial glands. Lactoferrin was found in serous acini, demilunes, intercalated and intralobular ducts. Lysozyme was found in acinar and intercalated duels, but was rarely seen in intralobular ducts. These results disclose the presence of cells (plasma cells and epithelial cells) and their products (IgA and secretory component) that indicate the local production of secretory IgA in minor salivary glands.
In situ characterization of cell infiltrates in human dental periapical granulomas 2. Demonstration of receptors for the complement components C3b and C3d
Authors: Skaug N. , Johannessen A. C. , Matre R. , Nilsen R.
Published: April 2006

The inflammatory cell infiltrates in human dental periapical granulomas were studied through the demonstration of receptors (R) for fragments C3b and C3d of the complement component C3. C3bR and C3dR were detected in cryostat sections by the closed chamber hemadsorption technique. Sheep erythrocytes sensitized with rabbit IgM antibody and coaled with human C3b or C3d were used as indicator cells. Of the 62 granulomas studied. 23 showed strong or moderate C3bR activity, and weak C3dR activity was detected in 5 out of 25 specimens. The C3bR activity was abolished by treatment with 0.25 mM periodic acid, indicating that carbohydrate is a pan of the C3bR. Using an antiserum to C3R as first layer in indirect immunofluorescence experiments, the C3R was localized to cell membranes. The low C3dR activity indicates that a minor part of the mononuclear cells in the human periapical granulomas were B lymphocytes.
In situ characterization of cell infiltrates in human dental periapical granulomas 3. Demonstration of T lymphocytes
Authors: Skaug N. , Johannessen A. C. , Nilsen R. , Matre R.
Published: April 2006

Cryostat sections of 66 snap‐frozen dental periapical granulomas were examined for T lymphocytes by the closed chamber hemadsorption technique using sheep erythrocytes (E) treated with 2‐aminoethylisothiouronium bromide hydrobromide (AET) as indicator cells (AET‐E). T lymphocytes were also demonstrated by immunofluorescent staining using a rabbit anti‐T lymphocyte antiserum. Eighty‐six % of the granulomas showed adherence of AET‐E, and often a local AET‐E adherence pattern was seen, indicating a localized infiltration of T lymphocytes. Diffuse, moderate binding of AET‐E to sections of some granulomas may be due to recirculating T lymphocytes traversing the tissue. The results of the immunofluorescence test parallelled the results obtained in the hemadsorption lest. The results show that mononuclear cell infiltrates of periapical dental granulomas usually contain T lymphocytes. Although their pathogenetic function in dental periapical granulomas is still not known, infiltrates of T lymphocytes indicate that cellular immune reactions are involved.
Effects of the anti‐inflammatory agents indomethacin, metiamide and acetylsalicylic acid on the induction of hyperplasia in hamster cheek‐pouch epithelium and ear epidermis
Authors: Harris R. R. , Mackenzie I. C.
Published: April 2006

Previous studies have shown that agents such as indomethacin and hydrocortisone act to reduce the level of epidermal hyperplasia produced by various chemicals, but little information is available about the effects of such anti‐inflammatory agents on the induction of hyperplasia in oral mucosa. Hamster cheek‐pouch epithelium and ear epidermis were treated with indomethacin, metiamide and acetylsalicylic acid prior to treatment with turpentine, podophyllin or TPA. The levels of hyperplasia induced were monitored by rates of epithelial glycolysis, protein synthesis and mitosis. The response of the metabolic assays to epinephrine was also examined. Alone, turpentine, podophyllin and TPA each caused a 3–5 fold increase in the metabolic assays and loss of the normal tissue response to epinephrine. Tissues pretreated with indomethacin showed significant reductions in the levels of hyperplasia produced and they retained a normal response to epinephrine. No reduction in hyperplasia was observed following pretreatment with acetylsalicylic acid, an alternative inhibitor of prostaglandin synthesis or with metiamide, a histamine blocker. The results indicate that the production of epithelial hyperplasia by turpentine, podophyllin and TPA can be inhibited by indomethacin.
Dysplastic enamel in odontoma: a light microscopic, microradiographic and SEM study
Authors: Kerebel L.‐M. , Kerebel B.
Published: April 2006

Dysplastic enamel and calcifications at the enamel surface in 7 odontomas were studied, using correlated light microscopy of decalcified and undecalcified material, microradiography and SEM. Much of the dentin in the odontomas was not covered with enamel. When present, the enamel was immature and assumed a prismatic structure. The prisms were irregular in diameters and often distorted in shape. Enamel perikymata were irregularly distributed and associated with spherical calcifications. The calcifications adhering to the enamel surface or separated from it presented variations in size, morphology, staining reactions and radiodensity. The correlated techniques of light microscopy, microradiography and SEM indicated that all the calcifications adhering to the enamel surface and part of those separated from it may be related to a pathological process of amelogenesis. Most of the calcifications separated from enamel and often formed around nidi of ghost cells, are the result of a dystrophic mineralizing process, definitely distinct from amelogenesis.
Ameloblastic fibrosarcoma: an ultrastructural study of the mesenchymal component
Authors: Nasu M. , Matsubara O. , Yamamoto H.
Published: April 2006

The mesenchymal components of tumors from 2 patients with ameloblastic fibrosarcoma were studied ultrastructurally. The mesenchymal components consisted predominantly of fibroblastic cells with a few histiocytie or fibrohistiocytic cells and myofibroblastic cells. In addition, a very small number of undifferentiated mesenchymal cells were found. We speculate that the mesenchymal components in this tumor may be derived from the undifferentiated mesenchymal cells.
Mineral flux of surface enamel and root surfaces in acidified gelatin gels
Authors: Feagin F. F.
Published: April 2006

Gels of crude gelatin were dialyzed to eliminate fluoride, and then acidified with 75 mM lactic and 25 mM acetic acid at pH 4.2 and interfaced with enamel and root surfaces in gel‐surface ratio of 0.2 ml/0.15 cm2. Enamel and root surface to gel mineral flux was reduced by initial inclusion of 0.5 and 1.0 mM fluoride with 2.5 mM calcium and 1.5 mM phosphate in gels at pH 4.2. Inclusion of 0.25 mM fluoride in the gels without added mineral ions had no effect in the first 22‐day interface. The 0.25, 0.5 and 1.0 mM fluoride remarkably increased remineralization in a second 12‐day interface. This indicated that the first fluoride exposure initiated formation of fluorapalites in the enamel which required a lower degree of gel saturation for enhanced remineralization in the second acid exposure. Fluoride had the same effect, but greater effectiveness on enamel than root‐surface remineralization. Gels of crude gelatin may contain sufficient mineral ions to alter remineralization‐demineralization of enamel and root surface.
Lectin‐binding in premalignant lesions during submandibular gland carcinogenesis
Authors: Murase N. , Takai Y. , Hosaka M. , Asano K. , Mori M.
Published: April 2006

Complex carbohydrates in premalignant lesions of mouse submandibular gland tumors were examined by the lectin‐peroxidase conjugate method. Peroxidase‐conjugated lectins of PNA, RCA‐1, DBA, SBA, UEA‐1 and WGA were used to detect specific sugar residues of complex carbohydrates in premalignant lesions during experimental carcinogenesis. Marked reduction of PNA and SBA bindings occurred in duct‐like structures and cystic lesions which were transformed from granular convoluted tubule cells. Premalignant lesions bound slightly to PNA, RCA‐1, DBA, SBA and WGA and manifested increased UEA‐1 binding. Squamous metaplastic epithelia of premalignant lesions manifested increased binding to PNA, RCA‐1 and SBA as compared to those of duct‐like structure and cystic epithelia.
Assessment of Langerhans' cells in oral lichen planus using monoclonal antibodies
Authors: Sloberg K. , Jonsson R. , Jontell M.
Published: April 2006

In order to demonstrate Langerhans' cells in epithelium of oral lichen planus, monoclonal antibodies were used as immunological markers in combination with immunohistochemistry. By the use of anti‐Ia antibodies the Langerhans' cells were shown to express an increased number of Ia‐like antigens in comparison to the amounts found in healthy oral mucosa. The subepithelial infiltrate of mononuclear cells expressed identical Ia‐like antigens on their surfaces. With anti‐T6 antibodies as immunological markers, the number of Langerhans' cells was found to be virtually identical in diseased and healthy epithelium. Treatment of oral lichen planus with tretinoin resulted in a decrease of epithelial Ia‐like antigens compared with the number found in untreated lesions. However, treatment with tretinoin did not alter the frequency of Langerhans' cell marked with anti‐T6 antibodies. The present data demonstrate an increased amount of la‐like antigens per number of T6‐positive Langerhans' cells in diseased oral mucosa compared to healthy conditions. The increased expression of Ia‐like antigens on Langerhans' cells and the contemporary finding of Ia‐like antigens on the subepithelial T‐cells support the opinion that the pathogenesis of oral lichen planus is mainly a cell‐mediated type of immunological reaction.
The effects of fluoride on the gastric mucosa of the rat
Authors: Pashley D. H. , Allison N. B. , Easmann R. P. , McKinney R. V. , Horner J. A. , Whitford G. M.
Published: April 2006

Fluoride is widely used for the prevention of dental caries. Very low concentrations of fluoride are routinely ingested in optimally fluoridated drinking water of many communities. Higher concentrations of fluoride in toothpastes, mouthrinses and topically applied gels also may be ingested, especially by children. The potential effect of ingested fluoride on the gastric mucosa was the subject of this investigation. Solutions of 0, 1, or 10 mM NaF in 0.1 N HCl were placed in rat stomachs in vivo for up to one hour. The effects of fluoride on the structure and function of the gastric mucosa were determined. Histologic and SEM examinations revealed dose‐and time‐dependent damage to the surface mucous cells. The 10 mM, but not the 1 mM, NaF solution increased gastric mucosal permeability to small but not to large molecules.
Epithelial jaw cysts: 10 years of the WHO classification
Authors: Main D. M. G.
Published: April 2006

Numerous papers on epithelial jaw cysts have appeared in the decade since the publication in 1971 of the WHO histological classification of odontogenic tumours, jaw cysts, and allied lesions. Despite clarification of certain cyst varieties no major revisions are necessary. The following minor modifications are proposed. In the developmental odontogenic group, the terms keratocyst and follicular are preferred to primordial and dentigerous. The alveolar cyst of infants is categorised separately from the gingival cyst of adults. The developmental lateral periodontal cyst is included as a distinctive new type. In the non‐odontogenic group the globulomaxillary is deleted as a unique entity, whereas the midpalatal eyst of infants is a new inclusion. To the inflammatory category are added the inflammatory follicular and inflammatory lateral periodontal varieties.
Ultrastructural features of the dental follicle associated with formation of the tooth eruption pathway in the dog
Authors: Wise G. E. , Marks S. C. , Cahill D. R.
Published: April 2006

The dental follicle is a loose connective tissue layer that surrounds the developing and erupting tooth. The follicle is necessary for tooth eruption in dogs and specific cellular changes occur in the follicle at the onset of tooth eruption, in particular, within the coronal region of the follicle next to areas of subsequent bone resorption there is an increase in mononuclear cells which have the ultrastructure features of monocytes and contain specific granules characteristic of preosteoclasts. The follicle has an extensive microvasculature and monocytes are often seen adjacent to capillaries and venules. Monocytes increase in number in direct proportion to the increase in osteoclasts that form the eruption pathway and decrease in number as soon as this activity is completed. It is postulated that monocytes enter the follicle from the microvasculature and then migrate to the walls of the bony crypt to participate in the formation of the eruption pathway.
Maxillary sinus cancer: a study of 33 cases
Authors: Mundy E. A. , Neiders M. E. , Sako K. , Greene G. W.
Published: April 2006

A retrospective analysis of 33 eases of maxillary sinus cancer seen at R.P.M.I. between 1970 and 1979 was performed. The age of the patients ranged from 18–88 years, with a median age of 60.3. The male to female ratio was 2:1.3. Twenty‐seven (81.8%) of the cases were squamous cell carcinomas. Of the 33 cases, there were no cases in Stage 1, 2 cases in Stage 2, 8 and 23 in Stages 3 and 4, respectively. The 5‐year survival among the patients who were available for a long‐term follow‐up was 36.47, (8 of 22). The 5‐year survival was best for Stage 3 disease (75%) and Stage 4, without local and/or distant metastasis (57.14%). No patient with metastasis lived for more than 3 years. While poorer diagnosis could he related to the degree of local involvement and presence of metastasis, it could not be related to site of involvement, previous treatment, histological findings or delay in diagnosis. Correlation of treatment with prognosis is difficult because selection of treatment is based on a variety of factors, including stage of disease and patient acceptance of treatment. Of the 4 patients treated with surgery alone, all 4 survived for 5 years. Of the 8 patients treated with combined surgery and radiation, 4 survived for 5 years and 2 died without evidence of tumor before 2 years. Other treatments were far less successful.
Fibrosarcoma of the mandible presenting as a periodontal problem
Authors: Handlers J. P. , Ahrams A. M. , Melrose R. J. , Milder J.
Published: April 2006

Primary fibrosarcoma of bone of the head and neck region is rare. An unusual presentation of fibrosarcoma of the mandible simulating a periodontal problem in a young woman is reported. The differential diagnosis is discussed.