bluuebunny/crossref_metadata_2025 huggingface dataset:
The glandular odontogenic cyst: an apparent entity
Authors: Gardner D.G. , Kessler H.P. , Morency R. , Schaffner D. L.
Published: April 2006

This article reports 8 examples of a rare cyst of the jaws that appears to be a distinct entity and which we have named glandular odontogenic cyst because of its unusual histopathological features. This lesion occurs over a wide age range in both sexes, tends to recur, and may become very large. However, one example in this series remained small over a period of 9 years; another, somewhat atypical example, was associated with an ameloblastoma.
Immunohistochemical analyses of autoimmune sialadenitis in man
Authors: Kjörell U. , Östberg Y. , Virtanen I. , Thornell L.‐E.
Published: April 2006

The immunoreactivity pattern for different monoclonal antibodies to cytokeratins and to vimentin in epimyoepithelial islands typical for glands of patients with Sjögren's syndrome has been compared with that of normal parotid gland tissue. Two types of epithelial island cells were observed: one had an intermediate filament protein pattern similar to that of ordinary duct epithelial cells of normal parotid gland. The other had an intermediate filament protein pattern typical of myoepithelial and/or basal duct cells in normal glands. Thus, we conclude that the islands are composed of a mixed population of gland cells on the basis of their content of cytokeratins or of cytokeratins and vimentin. These cells might originate from pluripotential reserve cells or from ordinary duct, myoepithelial and/or basal duct cells which may have undergone metaplasia.
Abnormal cellular property of fibroblasts from congenital gingival fibromatosis
Authors: Shirasuna K. , Okura M. , Watatani K. , Hayashido Y. , Saka M. , Matsuya T.
Published: April 2006

Two strains of cultured cells were isolated and characterized from the gingiva of two siblings with congenital gingival fibromatosis. The growth rate of both fibroblast strains was slower than that of comparable cells obtained from the normal gingiva of control individuals. The amounts of substances, including collagen and glycosaminoglycans, biosynthesized by the diseased cells were much greater than those by the control cells from normal gingivae. Namely, 11.7‐13.7% of the protein synthesized by diseased cells was collagen, whereas collagen accounted for only 6.1‐8.5% of the total protein produced by normal cells. Moreover, the production of a large amount of extracellular substances by the diseased cells was confirmed by electron microscopic examination. These observations suggest that the fibromatosis tissues contain affected fibroblasts which have low growth activity but are active in the production of much greater amounts of collagen and other extracellular substances compared to normal fibroblasts.
Spontaneous temporomandibular joint arthropathy in MRL‐lpr/lpr mice
Authors: Haraldson T. , Jonsson R. , Tarkowski A.
Published: April 2006

The temporomandibular joint (TMJ) in spontaneously arthritic MRL lpr/lpr (MRL/1) mice has been histologically analysed. After decalcification and standardized preparation of the joint tissue, histological sections were examined for presence of synovial hypertrophy, synovial villi, pannus tissue, erosions, cysts and signs of periarticular inflammation. In 12 of 13 TMJs examined, histopathological changes indicating a state of arthropathy were found. The most prevalent finding was synovial proliferation, which was frequently detected at the insertion of the synovial membrane to the bone. Two or more signs of inflammatory involvement including synovial proliferation, pannus tissue and bone erosion were seen in 5 mice with a predominance among the oldest mice (>5 months of age). No lymphocytic cell infiltration was found in the analyzed synovial tissues of the TMJ. In contrast, lymphocytes were observed in the vicinity of periarticular blood vessels and tendons. It is concluded that the TMJ is frequently involved in the arthritic disease of autoimmune MRL/1 mice.
Cytotoxicity of dental composites and other materials in a new in vitro device
Authors: Hanks C.T. , Craig R.G. , Diehl M.L. , Pashley D.H.
Published: April 2006

Several in vitro methods have been developed over the years to improve correlation between screening tests and usage tests of dental restorative materials. Pulpal responses to restorative materials in usage tests are usually less severe than are responses of cells either in in vitro screening tests or in implantation tests where there is direct contact between experimental materials and vital cells. In the “in vitro pulp chamber” device tested in the present study, dentin disks were interspersed between composite resins (as well as other dental materials) and the medium which served as the nutrient source for the Balb/c 3T3 test cell system. The dentin restricted the diffusion of materials into the “pulp chamber” to clinically relevant levels. The light‐cured composite resins (Fulfil and P30), caused depression of protein synthesis only during the first 24 h postpolymerization, when placed on 0.5 mm but not 1.5 mm thick dentin dishes. The chemically‐set composites (SILAR and P10) caused no significant inhibition of protein synthesis (as compared to negative controls) at any postpolymerization time on either 0.5 mm or 1.5 mm dentin disks.
Gingival pigmentation beneath a metallic crown: light and electron microscopic observations and energy dispersive X‐ray analysis.
Authors: Sakai T. , Sakai H. , Hashimoto N. , Hirayasu R.
Published: April 2006

Light and electron microscopic studies and energy dispersive X‐ray analysis disclosed that the essential cause of gingival discoloration following the placement of a metallic crown, was marked deposition of melanin pigment. Deposition of melanin pigment was observed in epithelial cells, on basement membranes, and in fibroblasts, macrophages and among intercellular ground substance of the proprial layer. Brown or dark brown colored granules were observed in the deep portion of the proprial layer. Some metallic elements as silver and sulfur were detected. It was presumed that these materials were dental metals accidentally implanted in gingival tissues during the therapeutic procedure. The deposition of melanin pigment closely corresponded with mucosal tissue where these materials were present in the deep portion of the proprial layer. These findings suggested that these materials influenced the physiological metabolism of melanin and induced its pathological deposition in the proprial tissue.
Expression of endothelial cell markers PAL‐E and EN‐4 and la‐antigens in Kaposi's sarcoma
Authors: Nadimi H. , Saatee S. , Armin A. , Toto P. D.
Published: April 2006

Eleven biopsy specimens of Kaposi's sarcoma (KS) removed from the skin and oral mucosa were examined immunohistochemically with monoclonal antibodies PAL‐E and EN‐4, specific for human vascular endothelial cells, and with LN‐3 monoclonal antibody reactive with immune‐associated (la) antigens in the HLA‐DR locus. The early lesions of KS, corresponding to the patch phase, contained hyperplastic venules and an increased number of lymphatic capillaries. The lymphatic capillary endothelium was reactive with EN‐4, whereas, PAL‐E reacted only with blood vessel endothelial cells. The spindle cells, like lymphatic endothelial cells, were non‐reactive with PAL‐E but showed positive reaction with EN‐4 antibodies. The observed morphologic pattern of vasculogenesis and the demonstrated immune‐reactivity in KS support an origin from the venul‐lymphatic junction. This is an aberrant pattern but reminiscent of normal embryonal lymphatic channel development. The lymphatic capillaries and vascular slits were nonreactive with LN‐3 antibody, but it was positive on cell membranes in a number of spindle cells, suggesting the focal expression of la‐anitgens.
Chondrosarcoma. I. A selected literature review
Authors: Garrington G. E. , Collett W. K.
Published: April 2006

More than 200 articles and texts relating to Chondrosarcoma in the general skeleton, in the head and neck area, and in extraskeletal soft tissues, were reviewed and summarized. In the interest of space conservation and avoidance to the extent possible, of distracting referential interjections in the text, the entire list of materials reviewed has not been referenced. For example, articles that contribute essentially nothing more than single case reports are not included in the list of references. Effort has been made, however, to include articles of historical significance, articles reporting series of cases, and articles exploring ideas and concepts. The authors believe this review to be a comprehensive summary of the Chondrosarcoma literature. An analysis of 37 cases of Chondrosarcoma of the jaws will be published as Part II.
Examination of herpes virus DNA sequences for patterns that resemble transposable elements
Authors: Shillitoe E. J.
Published: April 2006

Herpes viruses are associated with many types of oral tumors and can be tumorigenic in vitro. The mechanisms by which they transform cells remain unknown, but it has been suggested that they contain insertion sequences. Two algorithms were developed to search DNA sequences for the presence of patterns that characterize such elements using either selection or scoring techniques. When randomly shuffled herpes virus sequences were examined each algorithm detected many such patterns but the scoring algorithm found fewer than the selection algorithm. In the herpes virus sequences that are known to contain such patterns the computer techniques found many more than previously reported, indicating that visual inspection alone is not adequate. The frequency of these patterns suggest that although the transforming regions of herpes virus DNA could contain transposable elements experimental confirmation is necessary.
Evaluation of chemical protection against radiogenic osteodentin synthesis
Authors: Geist J. R. , Shupe R. E. , Kafrawy A. H.
Published: April 2006

The effect of the radioprotector 2‐mercaptopropionylglycine (MPG) in preventing the synthesis of radiation‐induced osteodentin was examined. Fifty rats were exposed to single x‐ray doses of between 3 and 19 Gy localized to the maxillary incisor growth centers. Half of the animals received an injection of MPG before irradiation while saline was administered to the other rats. MPG produced statistically significant reductions in the severity of osteodentin generation, but not its frequency, at some radiation levels. The nature of osteodentin and possible mechanisms of chemical radioprotection by MPG are discussed.
Tobacco components induce alterations in keratinocyte lipid membrane fluidity and inhibit cell proliferation in culture
Authors: Sauk J. J. , Norris K.
Published: April 2006

Guinea pig epidermal keratinocytes were harvested and grown in vitro (20). The cells were treated with polyphenolic compounds, acetate/shikimate aromatics, that are ubiquitous in plants. In addition, the cells were exposed to tobacco glycoprotein (TCP), a plant‐derived substance prepared from cured tobacco (19). All of the polyphenolic compounds enhanced the attachment of cells to a defined substratum and inhibited cell proliferation. Tobacco glycoprotein (TOP), rutin conjugates and ellagic acid inhibited cell spreading and enhanced the apparent microviscosity of keratinocyte membrane lipids. These data suggest that the use of these compounds may be associated with alterations in cytoskeletal architecture and membrane fluid dynamics that might result in clinical alterations characterized by whitening of mucosae.
Early invasion of squamous cell carcinoma of the tongue: of 31 cases
Authors: Hasegawa K. , Kayano T.
Published: April 2006

Thirty‐one cases of early invasive squamous cell carcinoma (SCC) of the lateral border of the tongue were analyzed histologically; 9 were also serially sectioned. Three‐dimensional reconstruction graphics showed that most of the invasive islands were connected with the adjacent epithelium, in spite of the apparent separation of islands on one histological section. Deep elongation, branching‐off of rete processes and the narrowing of each junction of branches were frequently observed. Early invasive patterns were characteristic and classified into the following 4 prototypes: droplet(17 cases); elongating(12 cases); invaginating(1 case); and reticular(1 case) invasion. Marked cellular atypia was not often seen either in the carcinoma or the adjacent epithelium. Some of these cases showed little cellular atypia. These results suggested that not only cellular atypia, but also such morphological architectures (structural atypia), as the elongation and branching‐off of rete processes, the increased number of separated islands, epithelial invagination, and the shortening of the distances between the surface epithelium and the underlying muscle layer, must be taken into consideration as being histological features of carcinomatous changes.
Dentin in chronic renal failure: an ultrastructural study
Authors: Clark D. B. , Wysocki G. P.
Published: April 2006

Disturbances in the mineralization of hard tissues in patients suffering from chronic renal failure and in patients undergoing chronic hemodialysis are a well‐established phenomenon. These disturbances are the result of complex pathophysiologic alterations in calcium and phosphorus metabolism. Disturbances in the dentin of teeth, analagous to those occurring in bone, were not recognized until 1983 when it was reported that a significantly thicker pre‐dentin layer was present in the teeth of patients with chronic renal failure and in patients being treated with chronic hemodialysis (1). The aim of the present study was to conduct a comparative ultrastructural (SEM) analysis of dentin in this group of patients. A wide spectrum of changes was detected, ranging from mild disturbances with increasing tubule irregularity and focal obliteration of tubule lumens, to widespread formation of dysplastic dentin exhibiting numerous mineralized, largely atubular globules with only occasional large, irregular tubules. In general, these changes appeared to reflect the type and effectiveness of treatment rendered (renal transplant or hemodialysis therapy). The findings suggest that dentin exhibits significant ultrastructural alterations when the underlying homeostatic regulation of calcium and phosphorus metabolism is disturbed in systemic disorders such as chronic renal failure.
Symptomatic residual radicular cysts
Authors: High A. S. , Hirschmann P. N.
Published: April 2006

The clinical, radiological and histological characteristics of 31 symptomatic residual radicular cysts are compared and contrasted with 39 asymptomatic residual cysts. Differences in size and site incidence are demonstrated along with an inversely proportional relationship between radiographic cortication and degree of acute inflammation in the cyst wall. A number of possible aetiological factors, to account for initiation of active inflammation in deeply placed residual cysts have been examined and excluded, but explanation, in most cases, remains paradoxical.
Toluidine blue staining for detection of oral premalignant lesions and carcinomas
Authors: Miller R. L. , Simms B. W. , Gould A. R.
Published: April 2006

The discriminative value of toluidine blue vital staining for detecting oral premalignant lesions and carcinomas was tested in the hamster DMBA buccal pouch model. The stain technique was further tested for specificity using the turpentine liquid petrolatum (TLP) hamster cheek pouch model for hyperplasia. Although carcinomas frequently exhibited toluidine blue staining, a 27.8% false negative result was noted. Premalignant lesions (dysplasia and carcinoma in situ) seldom retained toluidine blue stain and yielded a histologically confirmed (95.2%) false negative result. DMBA induced papillomas yielded a 5% false positive result. The TLP model failed to produce either clinically or histologically evident hyperplastic/hyperkeratotic lesions.
Immunocytochemical examination of immune cells in periapical granulomata and odontogenic cysts
Authors: Gao Z. , Mackenzie I. C. , Rittman B. R. , Korszun A.‐K. , Williams D. M. , Cruchley A. T.
Published: April 2006

Monoclonal antibodies (mAbs) were used to determine the presence and distribution of immune cells including lymphocytes, macrophages and Langerhans cells, in normal periodontal ligament, periapical granulomata, periapical cysts and dental developmental cysts. Isolated T‐lymphocytes, but not B‐lymphocytes, were detected in specimens of non‐inflamed periodontal ligament. Increased numbers of T and B lymphocytes were found in all of the lesions examined. Monocytes/macrophages were associated with most periapical granulomata, dental developmental cysts and all periapical cysts. Langerhans cells, intraepithelial lymphocytes, and monocytes/macrophages were not detected in the rests of Malassez but were found in some epithelia within periapical granulomata and in most epithelial linings of odontogenic cysts. Increased numbers of immune cells were seen around proliferative epithelia and adjacent to the epithelial linings of cysts. Epithelium, particularly that of odontogenic cysts, showed positive reactions for HLA‐Dr, lysozyme and for α‐1 antitrypsin. The presence of immune cells in periapical granulomata and odontogenic cysts, suggests that cell‐mediated and humoral immunoreactions occur in these lesions and may be associated with the epithelial proliferation within the periapical lesions.
Irradiation effect of low‐energy laser on rat submandibular salivary gland
Authors: Takeda Y.
Published: April 2006

Histopathological studies of rat submandibular salivary glands following low‐energy laser irradiation using gallium‐arsenide semi‐conductor laser were conducted. The mitoses of duct epithelial cells without atypia increased between 1 and 24 h after irradiation, reaching a maximum of greater than 5 times control values by 24 h. Mitoses of duct epithelial cells had a tendency to be more frequent in granular ducts, less in striated ducts, and still less in intercalated ducts. Qualitative differences in the effect of low‐energy lasers on salivary gland epithelia were also noted. This is the first experimental study of the effect of low‐energy laser on salivary glands.
Morphobiochemical analysis of calcified chondroblastic osteosarcoma of the mandible
Authors: Tokuoka T. , Kakuta S. , Yagami K. , Nagumo M.
Published: April 2006

Although the morphological features of osteosarcoma have been widely investigated, there is little information about its biochemistry. In this study, materials obtained from human calcified chondroblastic osteosarcoma were analyzed by microanalytical techniques revealing both morphological and biochemical characteristics at the same tissue site. Morphologically, tumor cells in the surface area showed atypical and mitotic figures. Hypertrophic chondroblastic cells appeared and increased in density closer to the calcified region. Almost all cells in the calcified region were hypertrophic. Biochemical analysis revealed that alkaline phosphatase activity was steeply elevated and inorganic phosphate gradually increased towards the calcified region. The spread of the calcified region was coincident with the contents of acid‐soluble phosphate and calcium of the tumor. These results were similar to those found in endochondral calcification of epiphyseal growth cartilage.
Ameloblastic fibroma: growth potentiality of odontogenic epithelium and coexpression of intermediate filament proteins in fibromatous cells
Authors: Tatemoto Y. , Yamamoto N. , Onojima M. , Okada Y. , Mori M.
Published: April 2006

Four cases of ameloblastic fibroma are described immunohistochemically in terms of intermediate‐sized proteins in both epithelial and mesodermal components. Keratin proteins were demonstrated by polyclonal anti‐keratin antiserum (TK: detecting 41–65 kDa keratins) and 2 monoclonal antibodies to keratin (KL1: 55–57 kDa, PKK1: 44, 46, 52 and 54 kDa), and monoclonal antibodies to vimentin and desmin. Two types of odontogenic epithelial tumour cells were discriminated: undifferentiated odontogenic cells and common ameloblastoma cells. Keratin expression was found to be stronger in undifferentiated cells than in the ameloblastoma cells. Undifferentiated cells were PAS–positive, while ameloblastoma cells were negative. Fibroma cells were strongly positive for vimentin, and negative for desmin. Keratin proteins were also expressed slightly. Thus, coexpression of keratin and vimentin was seen in fibroma cells. Histogenesis is discussed from the standpoint of the distribution patterns of keratin and vimentin, as well as with respect to the histopathology.
Parakeratosis of the mucosa in zinc‐deficient rats
Authors: Giunta J. L. , Hutchinson M. , Wallwork J. C.
Published: April 2006

Epithelial parakeratosis has been observed in zinc‐deficient animals of several species. In the rat, it has been reported on the epidermis, footpad, esophagus, soft palate, buccal mucosa, and dorsal tongue. This study reports that the lower lip also shows a striking hyperparakeratosis, as well as epithelial hyperplasia and an increase in mitoses. The appearance of these features was rapid with changes noted at Day 7 and persisting through Day 14 and Day 28. On Day 32, zinc was restored to the diet at control levels and by 42 days the zinc‐deficient group showed dramatic increases in food intake, body weight, femur zinc and, in addition, mucosa of the lower lip resembled zinc‐adequate controls. These differences are statistically significant. Morphometric comparison of spinous cells from zinc‐deficients with those of the controls did not show significant differences.
Malignant development of lichen planus‐affected oral mucosa
Authors: Holmstrup P. , Thorn J. J. , Rindum J. , Pindborg J. J.
Published: April 2006

The present report describes malignant development in oral lichen planus (OLP) among 611 patients (409 F, 202 M) followed for periods from 1–26 years (mean: 7.5). During follow‐up, 9 patients (1.5%), 8 women (1.9%) and 1 man (0.5%) developed oral squamous cell carcinomas (SCC) in areas of lichen planus lesions. The age of the patients at diagnosis of carcinoma ranged from 56–79 years (mean: 70.4) and the length of follow‐up before malignant development ranged from 4.9–24 years (mean: 10.1). The estimated number expected to develop oral cancer in a sample of the general Danish population of similar size, age distribution and follow‐up was 0.18 (0.11 F, 0.07 M) i.e., OLP cases showed a 50‐fold increase (F = 70‐ M = 14‐fold). The observed number of cancer cases was significantly higher than the estimated number (p < 0.00001). Therefore, oral lichen planus fulfils the WHO criterion of a premalignant condition.
Submucous fibrosis (SF) in exbetel nut chewers: a report of 14 cases
Authors: Seedat H. A. , van Wyk C. W.
Published: April 2006

The clinical and histological features are described of 14 subjects with SF who had given up betel nut chewing. The typical clinical features of the disease: blanching of the mucosa, palpable fibrous bands and complaints of burning and dryness of the mouth were still present, even in subjects who had not practised the habit for as long as 13 years. The characteristic histological features of the disease: atrophy of the oral epithelium and extensive fibrosis of the lamina propria, which in some instances penetrated into the submucosa, also persisted.
Immunohistochemical study of palatal salivary glands of denture wearing patients
Authors: Vigneswaran N. , Hornstein O. P. , Niedermeier W. , Gruschwitz M.
Published: April 2006

The binding pattern of antibodies against different cytokeratin (CK) polypeptides, tissue polypeptide antigen (TPA), carcinoembryonic antigen (CEA), lactoferrin (Lf), lysozyme (Ly) and secretory component (SC) in palatal glands (PSG) of long‐term denture wearing patients has been studied to investigate immunohistochemically the localization of these marker proteins in normal PSG and in denture‐induced sialadenitis of PSG. The study included palatal gland biopsies from 28 patients (15 f, 13 m; mean age 59 years), 17 of them with normal PSGs, 8 with focal obstructive sialadenitis, and 3 with diffuse sialadenitis. Presence of CK and TPA was found in all intra‐ and extraglandular salivary ducts, in the basophilic portions of acini, in some mucous acini, and in all atrophic acini. Increased expression of CEA and Lf was observed in inflammed areas of PSG which, on the other site, were devoid of Ly and SC. In the mucous acini of healthy PSG considerable basal Ly immunoreactivity was seen. SC was localized in almost all ductal cells and in some acinar cells. Appearance of Lf in the ductal cells of PSG indicates an early sign of palatal sialadenitis. Some distinctions in the expression pattern of the marker proteins between the mucous acini of major salivary glands and PSG point to differences in the functional activities of either group of salivary glands.
A method of semi‐quantitative microradiographic analysis of root surface lesion remineralization
Authors: Graves C. N. , Feagin F. F.
Published: April 2006

The purpose of this study was to present a modified photometer based digital analysis system for image enhanced microradiographic semi‐quantitation of reactions of demineralization and remineralization of root surface lesions. The system was used to determine effects of fluoride on abraded root surface dentin in vitro. Lesions of 30–40 μm depth were produced during 18 h exposure of 180 μm thick single sections in solution of 3 mM Ca (Ca/P 1.67) and 30 mM lactic acid at pH 5.1. Mean mineral content of the lesions was 32% relative to adjacent sound dentin. Exposure of 20 h in the same acid with 5 mM Ca (Ca/P 1.67) and 0.12 mM NaF at pH 6.1 restored the mean mineral content to 76% of normal and increased the resistance of the lesions to demineralization. Remineralization and subsequent demineralization characteristics indicated the growth of fluorapatites on residual minerals in the dentin lesions. The microradiographic analysis system proved to be sensitive and critical in these studies.
Differences between preneoplastic cells, neoplastic cells and their normal counterparts
Authors: Boyd N. M. , Reade P. C.
Published: April 2006

A number of changes occur in preneoplastic and neoplastic cells as they progress towards a greater degree of malignancy. These alterations include genetic changes, epigenetic changes, surface alterations and alterations in intercellular interactions. In some instances, these changes are contributing factors to the degree of pathology noted, whilst others are resultant. In many situations, the relationship between these changes and the progression towards neoplasia is not understood. Nevertheless, it seems probable that these changes are ultimately involved in driving cells further along the path to neoplastic transformation. It is the purpose of this review to consider the changes which occur as cells progress from normality to being neoplastic, with particular reference to the cells of the oral mucosa, and the use to which detectable changes can be used as prognostic indicators.
Ultrastructural immunocytochemical localization of secretory proteins in autophagic vacuoles of parotid acinar cells of starved rats
Authors: Hand A. R. , Ball W. D.
Published: April 2006

Previous studies have shown that reduction of mastication has marked effects on the structure and biochemistry of the rat parotid gland. Acute starvation results in the formation in the acinar cells of large autophagic vacuoles which contain lysosomal hydrolases and within which secretory granules appear to undergo degradation. In this study we used electron microscopic immunocytochemistry and antibodies to two secretory proteins, oamylase and Brimmunoreactive protein, to determine whether secretory proteins are present in autophagic vacuoles of parotid acinar cells of starved rats. Small vacuoles were observed after 24‐h starvation; they increased in size and number up to 72‐h starvation. Both secretory proteins were present in the secretory granules and in the dense content of the autophagic vacuoles, as shown by immunogold labelling. The lighter matrix of the vacuoles was unlabelled. These findings confirm that secretory granules may fuse with lysosomal structures, where their content of secretory proteins is presumably degraded. Thus, the rat parotid appears to be similar to other secretory cells in which cellular levels of stored secretory proteins may be regulated by the process of crinophagy.
Difference of immunohistochemical reactions in epithelial cells of adenolymphoma
Authors: Takahashi H. , Tsuda N. , Tezuka F. , Okabe H.
Published: April 2006

An immunoperoxidase staining technique was used for detecting alpha one‐antichymotrypsin (αl‐ACT), alpha one‐antitrypsin (αl‐AT), lactoferrin and transferrin in routine histological paraffin sections of 30 adenolymphomas, as well as in normal salivary gland tissue. Microscopically, the epithelial, component of adenolymphomas consisted of tall columnar luminal cells and irregularly shaped basal cells. αl‐ACT was detected in the luminal layer of epithelium in 27 (90%) of 30 adenolymphomas, while the basal layer was positive in 4 cases (13%). Lactoferrin could be observed in the columnar cells of 21 cases (70%) and was positive in the basal cells of 2 cases (7%). In normal salivary gland tissue, αl‐ACT and lactoferrin were observed in the intercalated duct and serous acinar cells. The staining pattern of αl‐AT in adenolymphoma was similar to those of αl‐ACT and lactoferrin, however, the number of positive cases for αl‐AT was fewer than in the αl‐ACT and lactoferrin. αl‐AT was not found in the normal salivary gland. On the contrary, the localization of transferrin in the epithelial component of adenolymphomas was exclusively different from those of αl‐ACT, αl‐AT and lactoferrin. Transferrin was found more often in the basal cells than in the tall columnar apical cells. The staining pattern of transferrin in the normal salivary gland was different from αl‐ACT and lactoferrin, and transferrin was positive in the cytoplasm of intercalated ducts, serous acinar and myoepithelial cells. Therefore, concomitant use of these 4 immunohistochemical stains may offer a way to study the functional condition of two‐layer epithelium of adenolymphoma. These results would indicate an intimate iinmunohistochemical expression between the normal intercalated duct and serous acinar cells and the epithelial component of adenolymphomas.
Vascular degeneration in adenomatoid odontogenic tumour: an ultrastructural study
Authors: EI‐Labban N. G. , Lee K. W.
Published: April 2006

Abstract The blood vessels in 3 cases of adenomatoid odontogenic tumour (AOT) were investigated ultrastructurally. An estimated 70–90% of the blood vessels found in the stroma showed degenerative changes which affected both the endothelial lining and the perivascular connective tissue. These vessels showed multiplication of basal lamina and were also encircled by concentric lamellae consisting either of collagen or fine filaments measuring 5–15 nm in diameter. Degradation of the layered collagen into fine filaments similar to those forming the concentric layers was observed. The present results suggest that the fine filaments of the concentric lamellae probably result from degradation of the layered collagen surrounding these vessels.
In vitro virucidal activity components of a forming medication
Authors: Rodu B. , Lakeman F.
Published: April 2006

This study evaluated the in vitro virucidal activity of soluble components of a topical film‐forming medication, Zilactin®, against Herpes simplex virus type 1 (HSV‐1). Using a standard plaque reduction assay, a 1:10 dilution of the experimental liquid resulted in total destruction of infectious HSV‐1. The phenomenon could not be explained by ethanol concentration or lowering of pH, both of which had no effect on control samples. As employed in this assay, Zilactin diluted 1:10 did not demonstrate cyctotoxicity to the cell monolayer system. The implications of these findings on the design and implementation of clinical trials are discussed, with special reference made to the restrictions imposed by the natural history of clinical lesions caused by HSV‐1.
Effect of bone matrix‐derived growth factors on skull and tibia in the growing rat
Authors: Engström C. , Jennings J. , Lundy M. , Baylink D. J.
Published: April 2006

Aberration in cranial skeletal morphology during growth due to metabolic bone diseases associated with hypocalcemia is related to abnormalities in cranial suture growth. It was found in previous experimental studies that a changed cranial growth pattern induced by hypocalcemia and secondary hyperparathyroidism was dependent on a decreased bone apposition in viscerocranial growth sites. Of interest was the observation that obliterative osteogenesis occurred with this disturbance. In vitro studies have shown that when bone resorption is stimulated by parathyroid hormone, mitogenic factors for bone cells are released from the matrix. The aim of the current study was to elucidate a possible local regulatory mechanism for bone growth especially with regard to cranial growth. Two groups of young rats were injected daily with 150 μg and 750 μg respectively of bone matrix‐derived growth factor preparation (BMDGF) for 2 weeks. By using cephalometric analysis, the BMDGF administration was shown to alter skull morphology during growth. Since the high doses of BMDGF caused markedly more changes than the low dose, the overall effect on craniofacial growth seemed to be dose dependent. The high dose of BMDGF induced a decrease in cortical bone apposition found in this region, as well as in the diaphysis of the tibia. Also a change in position of the viscerocranium in relation to the cranial base was found in the BMDGF‐treated rats: the flexure between the viscerocranium and the cranial base being greater compared with the normal skull. This change in relationship seemed to be related to the enhanced bone apposition found in the viscerocranial sutures of BMDGF‐treated rats. In as much as the preparation used was a crude preparation it is not possible to attribute the observed effects to any specific protein. However, the observations are consistent with the current knowledge on bone matrix‐derived factors. It is of interest that the skull morphology in the BMDGF‐treated rats were similar to the previous reports on rats with hyperparathyroidism in which obliterative osteogenesis in cranial sutures was observed. The altered viscerocranial morphology might thus be due to more differentiated cell functions in the suture as opposed to cortical bone.
Monoclonal antibody‐detected vimentin distribution in pleomorphic adenomas of salivary glands
Authors: Yamada K. , Shinohara H. , Takai Y. , Mori M.
Published: April 2006

To evaluate the participation of myoepithelial components in pleomorphic adenomas, an immunohistochemical study was carried out using monoclonal antibodies to vimentin. Of a total of 80 cases, 50 tumors gave positive staining, 5 tumors very slight, and 25 tumors negative staining for vimentin. Localization patterns for vimentin were divided into 3 classes: 1) vimentin staining in fibrous stromal tissue; 2) variable intensities of vimentin staining were found in the outer layers of tumor cells in tubuloductal structures (some of which were spindle cells connected to modified myoepithelial cells which also gave variable vimentin staining); and 3) modified myoepithelial cells and chondroidlike cells displayed strongly positive staining for vimentin. Typical histologic features of pleomorphic ademomas, i.e., tubulo‐ductal or duct‐like structures were characterized by positive vimentin staining in outer tumor cells and by a positive keratin reaction in the luminal tumor cells. In tumors devoid of stromal connective tissues and the near absence of well‐developed, or modified myoepithelial cells, vimentin staining was absent.
The pathogenesis of oral pulse granuloma: an animal model
Authors: Talacko A. A. , Radden B. G.
Published: April 2006

Oral pulse granuloma is one of the terms used to describe oral inflammatory lesions characterized microscopically by the presence of giant cells and hyaline rings. The various names proposed for these lesions reflect the lack of agreement regarding their pathogenesis. One theory advanced claims that the process represents a foreign‐body granulomatous reaction to implanted vegetable particles, more specifically those of pulses/legumes. In this study an animal model was developed where homogenized cooked legumes were implanted into the orofacial region of rats. Animals were killed at varying intervals ranging from one day to six months and the tissues associated with the implanted material were removed and processed for light microscopy. The experimentally produced lesions had many features similar to those found in humans, the similarities becoming more pronounced with time. The results indicate that the cellulose moiety of food particles of plant origin accidentally implanted into human tissues may cause the granulomatous reaction known as oral pulse granuloma.
Pathological sequelae of “neglected” impacted third molars
Authors: Stanley H.R. , Alattar M. , Collett W. K. , Stringfellow H. R. , Spiegel E. H.
Published: April 2006

An NIH conference on “Removal of Third Molars” debated the need for removal of asymptomatic impacted teeth with no evidence of pathology but stressed the need for long‐range studies. The assumption is that “neglected” impacted third molars (ITMs) will sometime cause serious pathology. Examination of panoramic radiographs of 11,598 patients revealed 1,756 patients with 3,702 impacted teeth; average age 47 years, and an average retention period approximately 27 years. Dentigerous cystic changes occurred in about 30 ITMs (0.81%), internal resorption in 16 (0.43%), periodontal ligament damage and bone loss distal to the 2nd molar 166 times (4.48%), and pressure resorption of the 2nd molar 113 times (3.05%). No great surge in pathology occurred with increasing age. Some type of pathological change can be expected eventually in approximately 12.0% of an impacted 3rd molar population and 1.82% of the general population. A reappraisal of routine removal of ITMs might be indicated.
HNK‐1+ (Leu‐7) cells and natural killer cell activity in inflamed human gingival tissue
Authors: Komiyama K. , Hirsch H.Z. , Moro I. , Umemura S. , Mestecky J.
Published: April 2006

The presence of HNK‐1 (Leu‐7)‐positive cells and natural killer (NK) cell activity was determined in human periodontal tissues. Gingival tissues obtained from 25 adult patients were processed for analysis utilizing a HNK‐1 (Leu‐7) mouse monoclonal antibody. A subpopulation of non‐adherent lymphoid cells obtained by collagenase digestion of inflamed gingival tissues from 10 patients was examined for the presence of large granular lymphocytes (LGL) by May‐Grünwald‐Giemsa staining and for NK cell activity against K562 cells by a 51Cr release cytotoxicity assay. HNK‐1+ cells were identified in gingival tissue sections of 21 patients, and were present in or close to discrete foci of plasma cells. HNK‐1+ cells were scarce in mildly inflamed or uninflamed tissues sections. LGL were identified in 9 of 10 gingival single‐cell suspensions and constituted approximately 5% of the gingival cell population. NK cell‐mediated cytolysis, at varying effector/target cell ratios, was observed for 3 of 4 enriched gingival mononuclear cell populations. Gamma‐interferon (INF‐γ) preincubation of enriched gingival effector cells from 5 additional patients resulted in a 43% increase in NK cell activity. The finding of increased HNK‐1+ cells with gingival inflammation suggests that these cells may play a role in tissue damage, as well as in modulation of B cell activity, in gingivae of patients with periodontal disease.
Transmission electron microscopy of the morphological relationship between fibroblasts and pulp calcifications in temporary teeth
Authors: Dard M. , Kerebel B. , Orly I. , Kerebel L. M.
Published: April 2006

Calcifications found in the coronal pulps of primary teeth extracted in an 8‐year‐old child were studied by TEM. Different types of relationship were observed between fibroblasts and pulp calcifications: extension of cell processes towards calcifications, modelling of the cells upon calcifications, internalizing process of calcifications. Fibroblasts proved to be able to enclose small pulp calcifications within intracytoplasmic vesicles. There was no evidence of any active role played by fibroblasts in the genesis of pulp calcifications. It was shown that collagen fibres could be involved or not in the mineralizing process. It is suggested that mitochondria might provide an adequate environment for initial mineralization. It is likely that the role played by the cytoskeleton in the internalizing process of calcifications is important.
la+ epithelial dendritic cells during oral carcinogenesis in the rat
Authors: Pitigala‐Arachchi A. , Matthews J. B. , Crane I. J. , Scully C. , Prime S. S.
Published: April 2006

Epithelial dendritic cells (EDC) were examined during the induction and growth of oral squamous cell carcinomas in rats treated with the carcinogen 4‐Nitroquinoline N‐oxide (4NQO). Acetone‐fixed frozen sections of the palate and tongue were stained using an indirect immunoperoxidase technique and a monoclonal antibody to rat la (MRC OX‐6). After 6 months there was a significant increase in Ia+ EDC/mm2 in non‐invasive palatal and lingual epithelium compared with untreated and solvent painted controls. Furthermore, after 9 months there were significantly more Ia+ EDC/mm2 in non‐invasive lingual epithelium compared with invasive epithelium or the epithelium overlying/adjacent to squamous cell carcinomas of the tongue. Although there were no significant differences of Ia+ EDC/mm2 between infiltrating epithelium of lingual carcinomas and non‐invasive epithelium overlying/adjacent to the tumour, these tissues did contain significantly more Ia+ EDC than lingual epithelium from either solvent‐only or untreated controls. The results indicate that treatment with 4NQO stimulates an increase in Ia+ EDC numbers which, although remaining higher than in controls, is not maintained within, or adjacent to, sites of neoplastic change.
Patterns of expression of intermediate filaments in ameloblastoma and human fetal tooth germ
Authors: Heikinheimo Kristiina , Hormia Marketta , Stenman Göran , Virtanen Ismo , Happonen Risto‐Pekka
Published: April 2006

Monoclonal antibodies (Mab) were used to study the expression of cytokeratins and vimentin in various histological types of ameloblastoma and in human fetal tooth germ. The ameloblastoma and the tooth germ epithelia showed characteristics of both simple glandular and stratified squamous epithelial cells. Cytokeratin No. 18 was detected focally in most ameloblastomas studied but not in fetal odontogenic epithelia. Cytokeratins Nos. 8 and 19 were expressed in all epithelial elements of ameloblastomas and tooth germs. Only two tumors showed focally characteristics of keratinizing epithelia also seen in dental lamina but not in the enamel organ. All tumors except the granular cell ameloblastoma showed a variable coexpression of vimentin and cytokeratins in their neoplastic epithelia. A similar coexpression was detected in the stellate reticulum cells of the developing tooth. Ameloblastoma and human tooth germ epithelia share complex pattern of cytokeratin polypeptides together with coexpression of vimentin. The results strongly support the theory that ameloblastomas are of odontogenic origin and not direct derivatives of basal cells of oral epithelium or epidermis.
Mast cells in human odontogenic cysts
Authors: Smith G. , Smith A. J. , Basu M. K.
Published: April 2006

Mast cells have been shown to be present in substantial numbers in both non‐keratinizing and keratinizing odontogenic cysts and could be seen in the connective tissue capsule and the epithelial lining. Within the cyst capsule, mast cells were more prevalent just beneath the epithelium than in deeper areas. This distribution pattern for mast cells is in accord with the histochemical picture for heparin staining in odontogenic cysts. In the non‐keratinizing cysts, there appeared to be some trend towards mast cells being associated with increasing inflammation but not in the odontogenic keratocyst. No evidence could be found for distinct mast cell subpopulations in odontogenic cysts. The presence of mast cells in odontogenic cyst could contribute to their pathogenesis in several ways.
Replacement of Langerhans cells in murine palate
Authors: Rittman B. R. , Mackenzie I. C. , Rittman G. A.
Published: April 2006

Palates from C3H mice were implanted onto prepared graft beds in histocompatible Fl hybrid mice. Biopsies taken 1, 2, 4, 8, and 16 wk later were prepared to demonstrate Langerhans cells (LC) of C3H and Fl (host) origin. After 1 wk only occasional LC (all of C3H origin) were present. By 2 wk total LC numbers had increased to a level approximately 50% greater than in control (non‐implanted) palate, with most of this increase due to C3H LC proliferation. From 4 through 16 wk total LC numbers were not significantly different from those of control palate. During weeks 2 through 16 the percentages of LC of Fl origin were 31, 70, 39, and 19% respectively. These results indicate an increased proliferation of C3H LC with an initial migration of Fl LC which stops as C3H LC numbers increase.
Cytokeratins in hamster cheek pouch epithelium during DMBA‐induced carcinogenesis
Authors: Lin L. M. , Chen Y. K. , Huang Y. L. , Mostofi R. , Toto P.
Published: April 2006

The pattern of keratin expression in hamster cheek pouch epithelium during 15‐wk of DMBA‐induced carcinogenesis was studied. The sequential changes in Cytokeratins of premalignant and malignant tissues and comparative investigation of normal epithelial tissues were examined during a weekly sequential DMBA‐induced chemical carcinogenesis. Keratin polypeptides of normal pouch epithelium appear in a molecular weight range of 43–67 kd and 5–6 proteins can be identified. The disappearance of high molecular weight keratin (61–67 kd) was observed from the 6‐wk DMBA‐treated premalignant group to the 15‐wk DMBA‐treated malignant group. An additional keratin polypeptide was noted initially on the 11th‐wk‐DMBA‐treated group and remained to the 15th‐wk‐DMBA treated group.
Immunohistochemical and fluorescent microscopic study of histogenesis of salivary mucoepidermoid carcinoma
Authors: Hassanin Mohamed B. , Ghosh L. , Das A. K. , Waterhouse J. P.
Published: April 2006

The purpose of the present investigation was to study the histogenesis of the mucoepidermoid carcinoma of the salivary glands. Eleven cases of mucoepidermoid carcinoma of the minor salivary glands and five of the major glands were extensively studied employing immunohistochemical and fluorescent microscopic techniques. Both the intermediate cells and the duct cells showed a rather similar pattern of reactivity for vimentin, actin and EMA. Also, the intermediate cells and the myoepithelial cells showed a similar reaction pattern for keratin and UGA‐1. The intermediate, myoepithelial and duct cells shared a similar reaction pattern for desmin, myosin, CEA, and S‐100 protein. However, the rest of the tumor markers studied (AFP, PNA and WGA) were found to be non contributary. We also found that the intermediate and to some extent the epidermoid tumor cells showed a positive reaction with Azophloxine GA, which is a selective stain for myoepithelial cells in the normal glands. Based on these findings, the duct cells, the myoepithelial cell in the normal glands and the intermediate cells of the mucoepidermoid carcinoma share certain similar characteristics. The intermediate cells may actually be a mixed population, some having characteristics of the myopithelial cells and others of duct cells. These findings are relevant to the possible role of the intermediate cell in the histogenesis of the mucoepidermoid carcinoma.