bluuebunny/crossref_metadata_2025 huggingface dataset:
Immunohistochemical localization of Type III collagen in the dentin of patients with osteogenesis imperfecta and hereditary opalescent dentin
Authors: Sauk J. J. , Gay R. , Miller E. J. , Gay S.
Published: April 2006

Abstract The immunohistochemical localization of Type III collagen was studied in the dentin from nine patients with dominantly inherited osteogenesis imperfecta (O.I.) and six patients with hereditary opalescent dentin (H.O.D.). The most consistent localization of Type III collagen was found in patients with O.I. Among these patients an indirect relationship existed between the severity of dentinal involvement and the presence of Type III antibody localization. Although a similar but less intense staining could be observed in some cases of H.O.D., the severity of dentinal alterations in H.O.D. was not correlative to the quantitative presence of material reacting with antibodies to Type III collagen. These observations further indicate that O.I. is not only clinically, but biochemically, a heterogeneous condition.
Hyaline bodies of odontogenic cysts: Histological, histochemical and electron microscopic studies
Authors: Yamaguchi Akira
Published: April 2006

Abstract Hyaline bodies of odontogenic cyst were examined by histological, histochemical and electron microscopic observations. They were seen only in odontogenic cysts and their prevalence was 6.9 % in 576 cases of the cysts. They occurred most frequently within the epithelial lining, but a few bodies were observed in the connective tissue walls. Histochemical reactions of hyaline bodies were similar to those of dental cuticles, but differed from keratin. Ultrastructurally, hyaline bodies were typed into two forms: lamellated and homogeneous. The lamellated bodies were composed of alternate electron‐dense and electron‐lucent layers. The homogeneous bodies were occasionally formed around granular material, mineralized masses and cholesterol clefts. Hyaline bodies adjoined epithelial cells via a basal lamina‐like structure and half‐desmosomes. Epithelial cells containing well‐developed, rough surfaced, endoplasmic reticulum were seen adjacent to hyaline bodies. Ferritin‐like granules were found in the cytoplasm of epithelial cells near hyaline bodies. By electron probe X‐ray microanalysis, inorganic elements within the Ferritin‐like granules were the same in constitution as those in the outermost electron‐dense layer of the lamellated bodies. By scanning electron microscopy, hyaline bodies displayed ellipsoidal and slick‐like shapes. The present study suggested that hyaline bodies arc particular products formed by odontogenic epithelium.
Odontoblast metabolism in rats deficient in vitamin D and calcium. IV. Lysosomal and energy metabolic enzymes
Authors: Engström Christer
Published: April 2006

Abstract Young rats, fed a low calcium and vitamin D deficient diet for 2 weeks, developed hypocalcemia, an increased activity of scrum alkaline phosphatase and an increase in the serum concentration of immunoreactive parathyroid hormone. An increased activity of lactate dehydrogenase and cytochrome oxidase in odontoblasts was found. No shift in the general energy metabolic pathway was found as visualized in the lactate dehydrogenase iso‐enzyme pattern. The dominating lactate dehydrogenase iso‐enzyme in odontoblasts from both the normal and the deficient rats was LDH I (H4, LD5), thus indicating primarily an aerobic energy‐metabolism. Also the activities of the lysosomal enzymes acid phosphatase, cathepsin D and hyaluronidase in the odontoblasts from the deficient animals were increased when compared to the normal animals. No significant change could be demonstrated for β‐glucuronidase and β‐N‐acetylglucosaminidase. It was earlier found that this deficient diet caused an increase in odontoblast alkaline phosphatase activities and protein synthesis in vitro. In view of the present findings it might be concluded that the low calcium and vitamin D deficient diet causes a general increase in the odontoblast metabolism. It is not known whether this is due to the increase in parathyroid hormone or if it is a direct effect of the lowered serum calcium concentration.
The response of four calcium hydroxides on monkey pulps
Authors: Heys D. R. , Heys R. J. , Cox C. F. , Avery J. K.
Published: April 2006

Abstract Dentinal bridge formation and pulpal responses of four calcium hydroxide materials, pulp capping medicaments, MFC®, Experimental MFC‐12, Dycal® and Pulpdent®, were evaluated in primary and permanent monkey teeth. A total of 60 primary and 60 permanent teeth were used with each material placed in a Class V cavity exposure in Rhesus monkey teeth. The materials were placed on the exposed pulp tissue and were histologically evaluated at 3 days, 5 weeks and 8 weeks. After perfusion the teeth were processed using routine histological procedures. The 3‐day pulpal responses in both primary and permanent teeth were moderate, characterized by disruption of the pulpal tissue directly beneath the exposure site and a zone of acute inflammation and hemorrhage in the underlying pulp. The 5‐week response showed histological differences between the four medicaments, with Dycal producing the least amount of pulpal irritation with reparative dentin bridges occurring in 50% of the permanent teeth. Experimental MFC‐12 stimulated one reparative dentin bridge, while Pulpdent and MFC showed no evidence of bridge formation. Pulpal responses to Dycal were moderate and moderate to severe for the other calcium hydroxide compounds. No reparative dentin bridges were seen in the primary teeth at 5 weeks with any of the materials, and the pulpal responses were of a moderate degree at that time. Eight‐week responses were similar to the 5‐week responses. Dycal provoked a slight to moderate pulpal response with 50% success at bridging. Experimental MFC‐12 initiated pulpal responses in the moderate to severe range with some bridging evident. Pulpdent incited moderate to severe histological responses with three teeth demonstrating bridge formation, and MFC provoked severe pulpal responses with no bridging. Primary teeth showed some bridging for all compounds except those treated with MFC, in which no evidence of bridging occurred, and moderate to severe pulpal responses were present.
Epithelio‐mesenchymal morphology in ameloblastic fibro‐odontoma: a light and electron microscopic study
Authors: Slootweg Pieter J.
Published: April 2006

Abstract Five cases of ameloblastic fibro‐odontoma were examined by light and electron microscopy. The ultrastructure of the epithelio‐mesenchymal interface was compared with the morphology of the normally developing tooth germ. It was noted that the ultrastructure of the tumors was identical with the normally developing odontogenic tissues up to but not including the differentiation of mesenchymal cells into tall columnar odontoblasts. The absence of odontoblasts in the ameloblastic fibro‐odontomas results in an absence of tubular dentin in place of which a homogeneous collagen‐containing material is synthesized. The failure of mesenchymal cells to acquire the morphology of tall columnar odontoblasts probably is due to the absence of the normally occurring induction of the mesenchyme by the odontogenic epithelium.
Ultrastructure of different clinical forms of oral leukoplakia*
Authors: Bánóczy Jolán , Juhász Jenö , Albrecht Maria
Published: April 2006

Abstract Twelve cases of oral leukoplakia were studied at the light and electron microscopic levels. In clinical leukoplakia simplex and verrucosa, both light and electron microscopic investigations revealed evidence of increased keratinization. Clinically erosive and histologically dysplastic leukoplakias showed ultrastructural alterations characteristic of oral carcinomas in some instances.
Ultrastructural changes in the translucent and dark zones of early enamel caries
Authors: Orams H. J. , Phakey P. P. , Rachinger W. A. , Zybert J. J.
Published: April 2006

Abstract Selected areas of early enamel caries (‘White spot’ lesion) in human teeth were argon‐ion‐beam thinned and examined by transmission electron microscopy. A systematic examination of areas which were histologically defined as the translucent zone and the dark zone showed that the pattern of early caries was consistent with that of demineralization of the tissue commencing with a widening of the micropores and of the inter‐rod spaces and gradually progressing to a severe destruction of the original enamel crystals, with possibly some remineralization. Observations indicate that the intercrystalline micropores and inter‐rod spaces are the pathways by which acidic agents reach the crystals causing carious dissolution.
Experimental dentigerous cysts and enamel hypoplasia: their possible significance in explaining the pathogenesis of human dentigerous cysts
Authors: Al‐Talabani N. G. , Smith C. J.
Published: April 2006

Abstract Cysts lined by epithelium were often found in association with tooth‐germ isografts in hamster cheek pouch. They developed from odontogenic epithelium and were in close relation to the crowns of involved teeth. Cysts associated with tooth‐germ isografts from 5‐day‐old animals (17 out of 36) commenced their formation shortly after transplantation as a result of enamel organ degeneration. Teeth associated with these cysts often showed enamel hypoplasia. Accordingly, 86 teeth involved in human dentigerous cysts were examined and 43 were found to possess areas of enamel hypoplasia on their occlusal surfaces or incisal edges. It is suggested that the pathological process initiating cystic degeneration in the enamel organ was also accompanied by degeneration of ameloblasts. When tooth‐germs from 2‐day‐old hamsters were transplanted, cystic spaces developed only after completion of enamel formation, 6 weeks following transplantation (in six out of 11 transplants), as a result of separation between the cells of the reduced enamel epithelium. Enamel hypoplasia was not a conspicuous feature. These experimental and clinical observations suggest that there may be at least two types of dentigerous cyst, perhaps with different causes, arising at different stages of tooth development.
The intact surface layer in natural enamel caries and acid‐dissolved hydroxyapatite pellets
Authors: Aoba Takaaki , Moriwaki Yutaka , Doi Yutaka , Okazaki Masayuki , Takahashi Junzo , Yagi Toshio
Published: April 2006

Abstract The crystallographic features of various histological sites found in enamel carious lesions were studied by means of X‐ray microbeam diffraction. The most interesting finding was that the crystallinity of apatite crystals in the intact surface layer covering the demineralized lesions was higher than that of the crystals in the subsurface lesions or unaffected areas. Acid‐dissolution experiments using synthetic hydroxyapatite pellets showed that a well mineralized layer was produced on the pellet surface under the condition that no Ca and PO4 ions were added to the initial acidic solution. Furthermore, X‐ray diffraction analysis revealed that half‐line breadth values of 004, 222, and 310 reflections of apatite pellets decreased, and their integrated peak intensities increased with dissolution time. These findings are in agreement with the results obtained in the study of enamel carious lesions, leading to the conclusion that the intact surface layer is formed by deposition of the mineral ions from dissolving subsurface lesions, and that this process is accompanied by the improvement in crystallinity of apatite crystals, possibly due to growth of the crystals.
Nuclear area and Feulgen DNA content of normal buccal mucosal smears
Authors: Cowpe J. G. , Longmore R. B.
Published: April 2006

Malignant cells usually have an abnormal DNA content demonstrable by cytophotometry of Feulgen stained tissue. The diagnostic reliability of the technique is reduced because some malignant cells have a normal Feulgen DNA content. If Feulgen DNA content can be combined with measurements of additional cytological characteristics known to vary in malignancy, reliable diagnostic criteria may be forthcoming. In this study, Feulgen DNA content and nuclear area were estimated in 50 squames from the buccal mucosa in each of 14 young adults. Nuclear Feulgen DNA content was determined using an M85 microdensitometer and nuclear area was measured using a Reichert MOP image analyser.

In each specimen, Feulgen DNA content was consistent with a nonreplicating cell population. Although nuclear area varied in each specimen, the variation in mean nuclear area among the sample of 14 was not statistically significant. It is concluded that nuclear area provides an accurate baseline against which future measurements on abnormal tissue can be compared.
Complement‐dependent histamine release from rat peritoneal mast cells, induced by lipopolysaccharides fromBacteroides oralis, Fusobacterium nucleatumandVeillonella parvula
Authors: Nygren H. , Dahlén G.
Published: April 2006

AbstractThe capacity of phenol/water extracted lipopolysaccharides (LPS) fromBacteroides, FusobacteriumandVeillonellato induce histamine release from rat peritoneal mast cells has been evaluated by means of a bioassay using atropinized guinea pig ileum and a fluorescence assay. Histamine release was found to be completely complement dependent. It was also found that LPS ofVeillonellahave the greatest capacity to induce histamine release andBacterioideshave the weakest.
Cytotoxic effects of dental cements on two cell culture systems
Authors: Hanks Carl T. , Anderson Marlene , Craig Robert G.
Published: April 2006

Abstract Four dental cements and one bis‐GMA composite were tested in cultures of human periodontal ligament fibroblasts and mouse 3T3 fibroblasts. It was found that these cell types reacted to the cements with different intensities, and that there were differences in evaluation by phase contrast microscopy and succinic dehydrogenase histochemistry.
Animal models of infra‐oral chemical carcinogenesis: A review
Authors: Eveson J. W.
Published: April 2006

Abstract Early attempts to induce malignant oral tumours were largely unsuccessful, us the oral mucosa is considerably more resistant to the actions of chemical carcinogens than skin. The first consistent success came when strong carcinogens were applied to the hamster cheek pouch. This model remains the most popular for studies of intra‐oral carcinogenesis and is discussed at length. The advantages and disadvantages are critically reviewed. The models of intra‐oral carcinogenesis in extra‐pouch sites in the hamster, mouse, rat and nonhuman primates arc considered. The possible reasons for the relative resistance of oral mucosa to chemical carcinogens are discussed, particularly in relation to portals of entry and saliva. Finally, the relative merits of the more popular models of intra‐oral carcinogenesis are briefly discussed.
Hyaline bodies in the connective tissue wall of odontogenic cysts
Authors: Chen Sow‐Yen , Fantasia John E. , Miller Arthur S.
Published: April 2006

Abstract Hyaline bodies are sometimes encountered in the connective tissue wall of odontogenic cysts. In this study, various histomorphologic types of hyaline bodies were observed in a dentigerous cyst and a residual apical periodontal cyst. Some hyaline bodies appeared to be a coagulum of serum fluid surrounded by a small number of fibroblasts. Others appeared to be composed of fibrillar structures. Still others appeared to be a mixture of various amounts of scrum coagulum and fibrillar structures. Immunoperoxidase procedures revealed various amounts of scrum proteins in hyaline bodies. Gomori's trichrome stain and Mallory's staining technique showed that fibrillar structures were collagenous in nature. Electron microscopy showed that fibrillar structures were frayed collagen fibrils. These observations suggest that various histologic types of hyaline bodies represent different stages of development and that the basic pathogenic mechanism is pooling of extravasated serum followed by fibrosis.
Bacterial bone resorption in noma (gangrenous stomatitis)
Authors: Mekkiu Bruce R. , Joseph Sam W. , Casazza L. J. , Duncan J. F.
Published: April 2006

Abstract Bone resportion (gangrenous stomatitis) was found to be associated with extensive bacterial colonization of mandibular bone in three separate cases of noma. Light and electron microscopy revealed a heterogeneous bacterial population with a long, filamentous, Gram‐positive organism predominantly in direct contact with the resorbing bone front. The bone was completely denuded and no osteoclastic activity was observed. The highly regular arrangement of the filamentous organism along the resorbing bone and the absence of osteoclastic activity suggested that bone resorption in noma is mediated by bacterial action.
Comparison of epithelial dysplasia in hamster cheek pouch carcinogenesis and human oral mucosa
Authors: MacDonald D. Gordon
Published: April 2006

Abstract Human oral epithelial lesions showing epithelial dysplasia were contrasted with hamster cheek pouch lesions induced by DMBA using the Smith & Pindborg (1969) technique for epithelial atypia scoring. It is concluded that the histological features of dysplasia in the hamster are closely similar to human lesions.
Cytoplasmic crystalloids in irradiated rat parotid glands
Authors: Sholley Milton M. , Pratt Neal E. , Sodicoff Marvin
Published: April 2006

Abstract Cytoplasmic crystalloids were found in paroid aeinar cells of rats given a large (6400 R) single exposure of X‐rays to the head and neck. The crystalloids were first observed 1 day after irradiation and became numerous at 3–4 days. They were associated with autophagie vucuoles, which were seen in acinar cells as early as 3–6 h. Crystalloids sometimes appeared to be forming within autophagic vacuoles, which also contained membranous residues and apparently degenerating secretory material. They were bounded by a single, smooth membrane and had a substructure consisting of dense, parallel longitudinal striations. The crystalloids were also seen in macrophages associated with the basal surfaces of acinar cells. At 3–4 days macrophages were numerous and many contained crystalloids, degenerated secretory droplets, and other cellular debris, which they apparently had phagocytosed. By 6–8 days crystalloids and macrophages were seen infrequently. Regarding mode of formation, removal by macrophages, and ultrastructure, the crystalloids resembled those described by others after ethionine intoxication. Ethionine‐induced crystalloids have cytochemical characteristics consistent with a lysosomal identity. The crystalloids in irradiated parotid glands probably reflect a variant type of lysosome, which is a nonspecific manifestation of severe cellular injury and can be elicited by a variety of injurious agents.
Effect of calcium on reactions between a salivary agglutinin and a serotype c strain of Streptococcus mutans
Authors: Rundegren J. , Ericson T.
Published: April 2006

Abstract Using a serotype c strain of Streptococcus mutans we found that the agglutinating activity could be quantitatively absorbed, and desorbed from the micro‐organisms by a phosphate buffer. The desorbed agglutinin was found to be inactive in the absence of calcium. Calcium alone did not induce aggregation. At 0.1 mM calcium most of the activity was regained. Other cations could not substitute for calcium. On a molecular basis the ratio between calcium and agglutinin or bacteria is high, in the order of 107 and 104 respectively.
A theoretical consideration of some biological parameters involved in cell kinetic investigations of oral leukoplakia and abnormal states in stratified squamous epithelium
Authors: Hume W. J.
Published: April 2006

The correct interpretation of cell kinetic data for normal epithelia requires a consideration of several interrelating factors. In abnormal states, such as leukoplakia, the lack of appropriate data for these parameters makes such interpretation difficult. Consequently, an altered mitotic index need not indicate an abnormality of cell proliferation.
Immunofluorescent studies in desquamative gingivitis
Authors: Laskaris G. , Demetriou N. , Angelopoulos A.
Published: April 2006

Twenty‐seven patients (19 females and 8 males) with a clinically diagnosed desquamative gingivitis were used in this study. Twenty‐seven additional patients with oral and skin diseases and with gingival involvement other than that of the de‐squamative gingivitis type served as controls. Biopsy gingival specimens were sectioned and stained with H and E. The rest of the tissue specimen was cut with a cryostat and used for immunofluorescent assays of the tissue‐bound antibodies (IgG, IgA, IgM, C3 and fibrin). Circulating antibodies were determined by using the indirect immunofluorescence method in serum samples. Normal human oral mucosa and several animal epithelial tissues were used as substrates. The immunopathologic findings suggest the diagnosis of lichen planus in the presence of linear or granular fibrin deposition at the basement membrane zone/mucosal submucosal interface with or without cytoid bodies and cicalricial pemphigoid, in the presence of circulating and/or tissue‐bound immunoglobulins and C3 in a linear continuous pattern along the BMZ. It is suggested that an accurate diagnosis of the underlying disease of the desquamative gingivitis can be made on the basis of the clinical, histopalhologie, immunopathologic and follow‐up findings.
An investigation into the origin and nature of ‘amyloid’ in a calcifying epithelial odontogenic tumour
Authors: Franklin C. D. , Martin M. V. , Clark A. , Smith C. J. , Hindles M. O.
Published: April 2006

Fresh and fixed tissue from a resection specimen of a calcifying epithelial odontogenic tumour (CEOT) was prepared for histological, histochemical, immunological and biochemical investigation in order to study the nature of the amyloid‐like material. The fixed tissue gave positive reactions with Congo‐red, Thioflavin T and the dimelhylamino benzene (DMAB)‐method for tryptophan. The diazotization‐coupling (DC) method for tyrosine was negative.

The major protein purified from the unfixed tissue by sequential gel filtration had a molecular weight of 9,800. The amino acid analysis of this protein had similarities with tuft enamel protein, immune amyloid and the variable light chain component (VK).

From the data obtained in this study, it is not possible to determine the precise nature of the amyloid‐like material in this CEOT. However, the results do support the concept that ‘amyloid’ should be considered as a term describing a broad group of related proteins.
Oral lipomas with osseous and chondrous metaplasia; report of two cases
Authors: Allard R. H. B. , Blok P. , van der Kwast W. A. M , van der Waal I.
Published: April 2006

Two oral lipomas with osseous and chondrous metaplasia respectively are presented. In the literature we were able to find only four similar lesions.
In situ characterization of cell infiltrates in human dental periapical granulomas
Authors: Skaug Nils , Nilsen Rune , Matre Roald , Bernhoft Carl‐Henrik , Johannessen Anne Christine
Published: April 2006

The aims of the present study were to demonstrate FcR activity of dental periapical granulomas and to correlate the activity with the degree of lymphoreticular cell infiltration. Cryostat sections of 46 out of 51 granulomas adsorbed sheep erythrocytes (E) sensitized with rabbit IgG antibodies (A) (EA). No adsorption occurred using erythrocytes sensitized with F(ab′)2 fragments of IgG. IgG and Fc fragments of human or rabbit IgG inhibited the binding of EA, whereas F(ab′)2 fragments, human IgA, IgM or albumin did not, indicating the presence of receptors for the Fc region of IgG. Periodate, neutral formaldehyde and phospholipase C abolished the FcR activity whereas neuraminidase had no effect. Comparison of sections binding EA and adjacent sections stained with haematoxylin and eosin showed that EA adhered to areas infiltrated with mononuclear cells. The degree of binding of EA coincided with the density of mononuclear cell infiltration. Point attachements between the tissue sections and the adsorbed EA could be demonstrated by scanning electron microscopy. Sections with no infiltrates did not bind EA.
Beta‐lactamase producing bacteria in the human oral cavity
Authors: Valdés Maria Villagran , Lobbins Phyllis M. , Slots Jørgen
Published: April 2006

Twenty‐six individuals who had no history of long‐term antibiotic therapy were examined for the prevalence of β‐lactamase producing bacteria in the oral cavity. Samples from a total of 159 normal and diseased periodontal sites, 44 cheek mucosae, 22 tongue dorsa and 22 salivas were studied. Penicillin resistant organisms were recovered from Trypticase soy blood agar plates containing 1 μg/ml or 2 μg/ml Benzylpenicillin. Beta‐lactamase formation by these isolates was determined using a micro‐iodometric assay. Low levels of penicillin resistant organisms were found in all samples. Approximately 10% of the samples yielded β‐lactamase producing strains. Except for a few Veillonella parvula strains, all β‐lactamase forming isolates were members of the Bacteriodes melaninogenicus subspecies melaninogenicus ‐ Bacteroides oralis group of organisms. These species can produce severe infections and, therefore, the present findings may be important in the clinical management of oral and nonoral infections.
Peripheral ameloblastoma: an ultrastructural analysis
Authors: Gould Alan R. , Farman Allan G. , DeJean Edgar K. , Van Arsdall Linda R.
Published: April 2006

Ultrastructural observations were compared for three different zones in a case of peripheral ameloblastoma, namely: the deep tumor islands, the “altered” surface epithelium overlying the tumor, and the transitional area between “normal” and “altered” covering epithelium. The possible origins and the behavior of this condition are discussed.
Epithelial cell kinetics. A review of methods of study and their application to oral mucosa in health and disease
Authors: Scragg Margaret A. , Johnson N. W.
Published: April 2006

In Part A, the techniques most commonly used to study epithelial cell kinetics and their suitability for use in man are reviewed. In Part B, the application of such methods to comparative studies of normal and abnormal oral epithelia of both man and experimental animals is examined. Claims regarding the possible prognostic value of LI's or MI's of biopsies of potentially or overtly malignant human oral lesions are also considered. Normal and abnormal kinetic data for other lining epithelia, e.g., skin, uterine cervix and gastrointestinal mucosa arc assessed where they provide a better illustration of some of the problems arising in such comparative investigations. Finally, the present and likely future areas in which cell kinetic studies may provide a guide to expected tumour prognosis and optimum treatment are summarized.
Establishment of a human cancer cell line from carcinoma of the gingiva
Authors: Koike Masao , Komori Akira
Published: April 2006

A new human epithelial cell line (MK—1) has been established from a well differentiated squamous cell carcinoma of the gingiva. It has been subcultured 90 times during the past 23 months. The population doubling time of the MK—1 cell line was 28 h. A colony forming ability with 18% plating efficiency was shown. Chromosomal analysis revealed an aneuploid human male karyotype with 22 marker chromosomes. The modal chromosome number was 75. Scanning electron micrographs of MK—1 cells showed numerous microvilli and intercellular bridges. Transmission electron micrographs of MK—1 cells showed epithelial characteristics with desmosomes, tonofilaments and membrane‐coating granules. Hetero‐transplantation of cultured MK—1 cells produced tumors, the histology of which was similar to that of original ones. The ultrastructure of the tumors showed the presence of abundant tonofibrils and keratohyalin granules. This MK—1 cell line is a model useful for the study of keratinization of squamous cell carcinomas.
Deposition of immunoglobulin and complement in mucocutaneous lesions related to treatment with D‐penicillamine
Authors: Egeland Torstein , Brandtzaeg Per
Published: April 2006

A 23‐year‐old man suffering from sero‐negative rheumatoid arthritis developed severe penicillamine‐induced mouth ulcerations and erythematous maeules. Immunohistochemical staining in a biopsy specimen from the affected lingual mueosa showed substantial deposition of IgM and C3 in vessel walls below the necrotic epithelium. In the affected skin, irregular granular staining for IgG and IgM along the epidermal basement membrane zone was noted, and granular deposits of IgM were present in small vessels of dermal papillae. The mouth ulcerations healed promptly after withdrawal of the drug, whereas the macules persisted for some months. The immunohistochemical findings indicated that the drug eruptions were related to a vasculitis induced by deposition of immune complexes.
Crystallographic and structural alterations in the mineral phase of human enamel with carious attacks
Authors: Aoba Takaaki , Yagi Toshio
Published: April 2006

The present study aims to obtain further information about the crystallographic and structural alterations in the mineral phase of enamel with the onset of caries. For this purpose, X‐ray microbeam diffraction analysis was carried out on ground sections prepared from natural while spot lesions. Electron spin resonance (ESR) analysis was also performed on block samples cut from white spot lesions and from undamaged enamel of the same teeth. The results of crystallinity measurements showed that enamel apatite in demineralized lesions was lower in crystallinity than the apatite in the surface layer and surrounding sound enamel. This X‐ray diffraction study also revealed the presence of two non‐apatitic minerals in the de‐mineralized lesions. One type of the mineral is whitlockite, giving spotty rings. The nature of the other mineral, giving a single ring‐like reflection, remains to be elucidated. A comparison of ESR spectra taken from the caries‐attacked and undamaged enamel provided evidence that the former samples have a lower degree of alignment of apatite microcrystals. The occurrence of non‐apatitic mineral phases and the observed difference in microcrystalline alignment may be the results of a remineralization process.
Thymidine kinase activity in oral squamous cell carcinoma
Authors: Scully Crispian
Published: April 2006

Thymidine kinase activity was assayed in scrum from 30 patients with oral squamous cell carcinoma and 30 controls. Thymidine kinase activity was significantly greater in patients with oral cancer than in controls and might be useful as a marker enzyme.
Pathological characteristics of oral lymphomas
Authors: Hashimoto N. , Kurihara K.
Published: April 2006

Nine cases of oral extranodal lymphomas arc described. Histologically, ft cases were histiocytic, 2 lymphocytic and I Burkitt's lymphoma. According to the criteria of the Japanese Lymphoma Study Group, 8 cases seemingly belonged to the B‐cell lymphoma classification, and one was unclassified. Geographical differences in the distribution of oral extranodal lymphomas between Japan and western countries were surveyed. A review of our cases and those in the literature revealed no significant difference in sex, age, frequency of B‐cell lymphomas or site of predilection. In Japan, histiocytic lymphomas were the most common type of extranodal oral lymphomas. The most prevalent type of oral extranodal lymphomas in western countries could not be determined from the literature.
Dark cells in human oral leukoplakias
Authors: Klein‐Szanto A. J. P. , Sega M. , Banoczy J. , Albrecht M.
Published: April 2006

Dark basal keratinocytes, characterized by a strong affinity for basic dyes and by electron density of cytoplasm and nucleus, could be recognized in eleven oral leukoplakias. The percentage of dark cells was higher in the group comprising leukoplakias verrucosa, and erosiva (28% of the basal cells) than in the leukoplakia simplex group (10%). The presence of these cells is a good indicator of the degree of histological dysplasia and correlates well with the preneoplastic potential of these lesions.
Protein components in saliva and plaque fluid from irradiated primates
Authors: Edgar W. M. , Bowen W. H. , Cole M. F.
Published: April 2006

Irradiation of the major salivary glands of monkeys (Macaca mulatta) led cariogenic diets leads to caries clinically indistinguishable from radiation caries in man. This study compares the organic compostion of individual samples of plaque fluid and saliva from irradiated and control monkeys receiving the same cariogenic diet. Plaque and saliva were collected from lasting, tranquillised animals. Four irradiated animals were sampled repeatedly as were non‐irradiated controls. Total protein, albumin, immunoglobulins A, G, and M, and the third component of complement (C′3) were quantitated in plaque fluid and whole saliva. Salivary amylase and peroxidase activities were also determined. Plaque fluid and saliva samples were also subjected to polyacrylamide gel electrophoresis. The total viable anaerobic count and numbers of Streptococcus mutans were determined in samples of plaque. The results suggest that the major effect of irradiation leading to increased numbers of S. mutans and caries susceptibility is in the amount, and not the composition, of the saliva produced by the residual gland tissue. The scanty flow of saliva may reduce the effectiveness of cleansing, buffering and lubrication mechanisms as well as resulting in a marked reduction in the total amount of specific and non‐specific immune factors entering the mouth.
Liposarcoma of the oral cavity. Clinical, tissue culture, and ultrastructure study of a case
Authors: Sadeghi Ezedin M. , Sauk John J.
Published: April 2006

This report presents the histologic, tissue culture, and ultrastructural findings in a well‐differentiated liposarcoma that originated in the buccal mucosa of a 42‐year‐old female. A variety of cell types were identified in the recurrent tumor with light and electron microscopy; namely, rounded mesenchymal cells, signet‐ring cells, multivacuolated cells and bizarre giant cells. The giant cells possessed large, multilobed nuclei with large nucleoli. Mitochondria appeared in varied numbers and Golgi zones were highly organized. Cytoplasmic inclusions were variable in the cytoplasm of the tumor cells. A morphologic variation among cells was also noted in the tissue culture media. The histogenesis of this unusual and sometimes difficult to interpret neoplasm of the oral cavity is discussed.
Correlative clinico‐pathological evaluation of oral premalignancy
Authors: Fischman Stuart L. , Ulmansky Mario , Sela Jona , Bab Itai , Gazit Dan
Published: April 2006

In 1972, the World Health Organization's “Meeting of Investigators on the Histological Definitions in Precancerous Lesions” defined a precancerous lesion as a “morphologically altered tissue in which cancer is more likely to occur than in its apparently normal counter part” (Pindborg 1980).

There are two generally accepted precancerous lesions in the oral cavity, leukoplakia and erythroplakia (Pindborg 1980). Leukoplakia is currently defined as “a white patch or plaque that cannot be characterized clinically or pathologically as any other disease” (WHO 1978). This definition has no histological connotation and is used in a strictly clinical sense (Pindborg 1980, Banoczy 1977). Erythroplakia is defined as a “bright red velvety plaque which cannot be characterized clinically or pathologically as being due to any other condition” (Pindborg 1980).
A method for the study of undecalcified bones and teeth with attached soft tissues*
Authors: Donath K. , Breuner G.
Published: April 2006

A new sawing‐grinding method is described for the histological evaluation of jaw bones with teeth or bones containing implants (ceramic or metallic). The undecalcified bone is embedded in acrylic resin and sawed at 100 to 150 μm. The slices are ground automatically by a special machine to a thickness of 5–10 μm. The usually employed staining procedures for hard plastic embedded tissues may be used. Plaque, fillings, crowns, bridges, implants and soft tissues are preserved in situ. Macroscopic and microscopic detail of good quality is preserved for histological and morphometrical evaluation.
Intraoral salivary gland tumors: a retrospective study of 201 cases
Authors: Isacsson G. , Shear M.
Published: April 2006

Two hundred and one cases of intraoral salivary gland tumors were studied from the files of the School of Pathology, University of the Witwaterstrand and South African Institute for Medical Research. 145 cases (72.5%) were classified as benign, comprising 140 pleomorphic adenomas and 5 monomorphic adenomas. The other 56 cases were classified as malignant or potentially malignant tumors, represented by 21 adenoid cystic carcinomas, 15 adenocarcinomas, 13 mucoepidermoid tumors, 5 carcinoma in pleomorphic adenomas and 2 epidermoid carcinomas. The patients in the malignant/potentially malignant group were significantly older than those in the benign group and a smaller proportion of their tumors were palatal, the difference being statistically significant. The high frequency of pleomorphic adenoma might result from a relatively higher number of black than white patients in this sample.
Effects of calcium ions on hamster cheek pouch epithelium grown in vitro
Authors: Singh B. B. , Schuster G. S. , Erbland J. F. , Ringler M. B.
Published: April 2006

Epithelial outgrowths from hamster cheek pouch explants were cultured for 14 days in media containing calcium concentrations of 0.05 mM, 0.075 mM, 0.1 mM, 0.25 mM, 0.75 mM or 1.45 mM (control). Compared with controls, the cultures grown at lower calcium concentrations (0.25–0.75 mM), exhibited higher mitotic indices and an increase in outgrowth size. The mitotic index of cultures at 0.25 mM calcium concentration was 30 ± 2.26, compared to 24 ± 2.24 for controls. Increase in size of the outgrowths was also observed at 0.25 mM calcium concentration compared with those grown in control medium. The epithelial outgrowths grown in control media exhibited cell stratification not observed at lower calcium concentrations. These studies indicate that lower calcium concentration in the media (0.25–0.75 mM) increased epithelial cell proliferation and inhibited keratinization.
Immature complex odontoma: a light and electron microscopic study with reference to eosinophilic material and epithelio‐mesenchymal interaction
Authors: Slootweg P. J. , Rademakers L. H. P. M.
Published: April 2006

A case of immature complex odontoma was examined by light and electron microscopy, looking for additional information on odontogenic, tissue‐associated eosinophilic material (EM). Moreover, the ultrastructural morphology of the lesion was related to normal odontogenesis. Firstly, EM appeared to represent two different kinds of material, both being akin to predentin. Secondly, it is supposed that heterotypic epithelio‐mesenchymal cellular contacts have to be interpreted in terms of ultimateodontoblastic differentiation and have nothing to do with stimulation of the transformation of pre‐ameloblasts into enamel producing ameloblasts. In the third place, it is supposed that aberrant histogenetic differentiation in the odontomas is due to a failure of the mesenchymal component to respond normally to epithelial inductive influences.
Serum ferritin in recurrent oral ulceration
Authors: Challacombe S. J. , Scully C. , Keevil B. , Lehner T.
Published: April 2006

A sensitive radio‐assay for ferritin was developed and used to examine serum ferritin levels in 105 patients with recurrent oral ulceration (ROU), 41 patients with Behçet's syndrome (BS), 42 with other ulcerative oral lesions, 35 patients with non‐ulcerative oral lesions and in 78 controls. Ferritin levels increased with age and were significantly higher in males than females. The mean ferritin concentrations in male patients with ROU, BS or with other oral ulcers were significantly reduced in comparison with controls, and in female patients were significantly reduced in those with major aphthous ulcers. The prevalence of low serum ferritin levels was about 8% in patients with ROU, 15% in BS and 9.5% in patients with other ulcerative oral lesions, compared with less than 3% in patients with non‐ulcerative oral disorders and in controls. Most of the iron‐deficient patients were female. Serum ferritin levels did not directly correlate with serum iron levels and may be a more accurate indicator of iron deficiency. Furthermore, serum ferritin can distinguish between patients with true iron deficiency and those with secondary sideropenia. It is suggested that in a small number of patients, oral ulceration may be a presenting sign of iron deficiency, and that in a further small proportion of patients, ROU already present will be exacerbated by concurrent iron deficiency. Both groups will show a therapeutic response to correction of the iron deficiency. The results suggest that serum ferritin levels are a useful part of the haematological investigations in patients with ROU.
Leukoedema: ultrastructural and histochemical observations
Authors: van Wyk C. W. , Ambrosio S. C.
Published: April 2006

The ultrastructural features of 12 cases of leukoedema were investigated and compared with clinically normal buccal mucosa. Histochemistry was undertaken to try to resolve some of the observed ultrastructural changes. The characteristic “intra‐cellular edema” of the epithelial cells in leukoedema is due to vacuolation in the cytoplasm of cells. Abnormal mitochondria were observed in these cells. The vacuoles contained a granular material somewhat like clumped glycogen granules, but histochemistry failed to identify this material as glycogen. Towards the surface of the epithelium, the vacuolated cells collapsed into a compact layer of flattened cells. The outer cells of this layer abruptly swelled again to form the characteristic superficial layer of “ballooning” cells of leukoedema. The latter cells were not vacuolated but contained remnants of organelles, membraned vesicles with remnants of organelles, keratohyalin granules and structures apparently related to keratohyalin granules. We propose that the vacuolation represents a limited reversible form of cellular degeneration resulting from cell damage and that impeded mitochondrial function may be the cause of the vacuolation. The superficial “ballooning” cells are degenerated cells. The flattening of the vacuolated cells into a compact layer and the presence of keratohyalin granules and keratohyalin‐like structures in the superficial cells are regarded as features of an aborted form of keratinization.
Tyrosine‐rich crystals in pleomorphic adenomas of parotid glands
Authors: Chaplin A. J. , Darke P. , Patel S.
Published: April 2006

Histochemical methods for proteins were applied to crystals found in pleomorphic adenomas of the parotid. Positive reactions were obtained with methods for tyrosine, tryptophan, arginine and sulphydryl groups, and indicate a greater complexity of composition than has previously been acknowledged.
4 Nitroquinoline 1‐oxide‐induced carcinogenesis in the rat palate
Authors: Wong P. N. C. , Wilson D. F.
Published: April 2006

Most reported studies of experimental oral cancer have been carried out in the hamster. This animal is not available in certain countries and there is controversy regarding its suitability as a model for experimental oral carcinogenesis. An attempt was made to reproduce an experimental oral cancer model in rats, using a protocol based on that described by Lekholm and Wallenius (1976). The carcinogen 4 nitroquinoline 1‐oxide was applied to the palates of rats for periods of up to 24 weeks. Macroscopic and microscopic examination of carcinogen‐treated palatal mucosa was carried out during the experimental period. Verrucous carcinoma‐like lesions of the mid‐palate and squamous carcinomas of the gingival mucosa were produced, beginning at 16 and 20 weeks respectively. A variety of other macroscopic and microscopic mucosal changes were also observed during the experimental period. The findings are discussed in relation to the work of others.
A morphologic study of the recovery of the rat submandibular gland after retrograde infusion
Authors: Qwarnstrom E. E. , Omnell K.‐A. H. , Hand A. R.
Published: April 2006

The recovery of the rat submandibular gland after retrograde infusion of water‐soluble radiographic contrast medium was studied using an experimental model. During continuous monitoring of the developing intraglandular pressure, the glands were subjected to ductal and slight parenchymal filling or heavy parenchymal filling with the medium. The animals were killed after varying recovery periods, and the tissue was prepared for light and electron microscopic examination. Dilation of the ductal lumina, induced during ductal and slight parenchymal filling, was successively reduced and, generally, the parenchyma had a normal appearance at 30 h. In glands subjected to heavy parenchymal filling, the changes in the intralobular ducts were more pronounced and were also seen at later times after infusion. Alterations in the acini, comprising fusion of secretory granules, vacuole formation and dilation of the acinar lumina and intercellular canaliculi, were observed. At later times, atrophy of the parenchymal cells occurred together with an apparent proliferation of the connective‐tissue stroma, as well as an increase in the number of small blood vessels. An inflammatory cell‐infiltrate was seen in both groups of animals, but was most prominent in glands subjected to heavy parenchymal filling. The infiltrate, comprised primarily of macrophages and polymorphonuclear leukocytes, reached a peak at 20 h after infusion. At later times, mast cells and occasional eosinophils were seen. The observed alterations and the pattern of recovery are most likely due to the induced intraglandular pressure and the following inflammatory reaction. It is also possible that the changes, to some extent, are influenced by the presence of the contrast medium in the tissue.
Specificity of the involvement of chromosomes 8 and 12 in human mixed salivary‐gland tumours
Authors: Stenman G. , Mark J.
Published: April 2006

Using the G‐banding technique the chromosomal patterns in 10 in vitro‐cultured human mixed salivary gland tumours were studied. When surveying the results from the present 10 adenomas together with previous results from 31 adenomas, the following characteristic features were found. Mixed tumours probably always originate with a normal diploid stemline. This stemline type was also found to predominate during progression. However, about 41% of the tumours showed abnormal stemlines characterized by highly specific, usually structural, clonal aberrations. The deviations in these abnormal stemlines seemed to preferentially affect certain chromosome types, viz. Nos. 8 and 12. This non‐random pattern of deviations ‐ not found earlier in either benign or malignant tumour types in man ‐indicates that certain regions of, especially, chromosomes 8 and 12 are selectively affected in mixed tumours. Among other things, changes of gene dosage and/or oncogene activation are mentioned as factors possibly influencing the characteristics of this non‐random pattern.
Severe oral lichen planus: remission and maintenance with Vitamin A analogues
Authors: Sloberg K. , Hersle K. , Mobacken H. , Thilander H.
Published: April 2006

Twenty‐five patients with chronic oral lichen planus, usually of the atrophic‐erosive type, were treated for 2 months with Etretinate® 0.6 mg/kg b.w./day, followed for 4 months by Etretinate® 0.3 mg/kg/day, or 0.1% Tretinoin® in an adhesive base. Complete resolution or improvement was seen in 85% of the lesions after first treatment. The number of patients with oral soreness and pain was significantly reduced (p < 0.001). During the second treatment, the improvement was maintained or even increased in about 70% of the patients, irrespective of the mode of treatment. Treatment was discontinued in one patient owing to moderately increased serum transaminase levels. The number of drug‐related drop‐outs was significantly lower than in a previous study utilizing an etretinate dose of about 1 mg/kg/day (p < 0.05). Other adverse effects were minor and tolerable. Retinoids offer an effective mode of therapy for severe oral lichen planus.