bluuebunny/crossref_metadata_2025 huggingface dataset:
Microcystic adnexal carcinoma: a light microscopic, immunohistochemical and ultrastructural study
Authors: Kato Haruhisa , Mizuno Nobuyuki , Nakagawa Koichi , Furukawa Masayoski , Hamada Toshio
Published: April 2006

We report a case of microcystic adnexal carcinoma (MAC) occurring on the upper lip of an 82‐year‐old woman. Microscopically the tumor showed both pilar and sweat gland differentiation, involved the entire dermis and subcutaneous tissue, and invaded perineural spaces. Immunoperoxidase studies revealed carcinoembrionic antigen to be present in the ductal lining cells and in the amorphous content in the lumen, confirming sweat gland differentiation. The S‐100 protein was positive in dendritic cells within the solid cell nests, but negative in cells lining cystic spaces. Ultrastructural study confirmed that the neoplasm was composed of two components, with pilar and eccrine differentiation. The former showed concentric layers of squamous epithelial cells with well‐developed desmosomes and cytofilaments. The latter had ductal and alveolar structures; the ultrastructural features included i) numerous villous folds of plasma membrane to interdigitate each other by focal desmosomes, ii) aggregates of cytofilaments, and iii) basally located myoepithelial cells which were separated from the surrounding stroma by rather thick basement membrane. In addition, distinct amyloid deposition was also observed on ultrastructural examination. To our knowledge, amyloid deposition has not been previously reported in MAC.
Cutaneous papillary squamous cell carcinoma. A report of two cases
Authors: Landman G. , Taylor R. M. , Friedman K. J.
Published: April 2006

Several histologic patterns of squamous cell carcinomas (SCC) have been described, including classical, adenoid, verrucous, and clear cell. We report 2 cases of an unusual purely exophytic papillary growth pattern. Both tumors occurred on sun‐exposed skin of elderly patients and exhibited rapid growth. The tumors were red‐tan and fungating, raising the clinical differential diagnoses of pyogenic granuloma, SCC, metastatic carcinoma or amelanotic melanoma. Histologically there was a prominent papillary growth pattern with several layers of notably atypical squamous epithelium overlying a fibro‐vascular core in both cases. Mitoses were frequent. The tumors lacked deep invasion, although focal invasion of the stalk was present. These tumors were histologically distinct from verrucous carcinoma, verrucous Bowen's disease, and previously described adnexal carcinomas. The lack of deep invasion and the absence of local recurrence or metastatic disease after 18 months follow‐up suggest that this histologic variant is a low‐grade malignancy, although study of more cases and longer follow‐up will be necessary to accurately assess the biology of this papillary variant of SCC. We believe that this growth pattern has not yet been described and a pure papillary form must be included as one of the histological subtypes of cutaneous SCC.
Cutaneous malakoplakia simulating relapsing malignant lymphoma
Authors: Palazzo J. P. , Ellison D. J. , Garcia I. E. , Langer C. , Scher R. M. , Hoffman J. P. , Petersen R. O.
Published: April 2006

This report describes the case of a 42‐year‐old man with malignant lymphoma, diffuse large non‐cleaved cell type, who developed cutaneous malakoplakia in the left groin. The patient had widespread lymph node involvement, including a left inguinal mass which was clinically thought to represent recurrent lymphoma. The inguinal mass failed to regress after chemotherapy and irradiation, although lymphoma in other sites responded to chemotherapy. A skin biopsy of the area showed an ulcer and an abscess involving the dermis and subcutaneous tissue. Microscopically, a diffuse infiltrate of foamy histiocytes was seen with numerous intracellular and extracellular, round and laminated bodies. Some of these bodies had a “targetoid” appearance, stained strongly with von‐Kossa's calcium stain and showed the typical appearance of Michaelis‐Gutmann bodies by electron microscopy. Cultured monocytes from the peripheral blood of the patient showed ultrastructural features similar to their tissue counterparts, suggesting a systemic involvement of the monocyte macrophage lineage. This case represents an unusual presentation of malakoplakia of the skin associated with relapsing malignant lymphoma in a patient on immunosuppressive drugs.
Solitary sclerotic fibroma
Authors: Lo W.L. , Wong C.K.
Published: April 2006

A 63‐year‐old Chinese man with a solitary sclerotic fibroma on the abdomen is described. Skin biopsy showed a well‐demarcated dermal nodule composed of hypocellular, eosinophilic collagen bundles separated by prominent clefts. Retrospective electron microscopic study revealed wide collagen bundles containing tightly packed collagen fibrils, only 50 nm in diameter. There were no signs of Cowden's disease. To our knowledge, this is the first report of electron microscopic study of sclerotic fibroma. A brief review of the literature is included.
An unusual cutaneous metastasis of a chondrosarcoma
Authors: Leal‐Khouri Susanna M. , Barnhill Raymond L. , Baden Howard P.
Published: April 2006

We report a case of cutaneous metastases from a scapular chondrosarcoma in a 85‐year‐old man. The metastatic skin lesion was noted nine years after resection of the primary tumor. Metastases to lung and soft tissues had occurred four years earlier. The patient also had a history of malignant melanoma. Although this case illustrates an unusual pattern of metastases, we conclude that the appearance of cutaneous lesions in a patient with a prior history of chondrosarcoma should alert the clinician to the possibility of a metastatic chondrosarcoma.
Characterization of the dermal infiltrates in Jessner's lymphocytic infiltrate of the skin, polymorphous light eruption and cutaneous lupus erythematosus: differential diagnostic and pathogenetic aspects
Authors: Rijlaarsdam J. U. , Nieboer C. , de Vries E. , Willemze R.
Published: April 2006

In the present study a comparative immunohistochemical study was performed on skin biopsies from of patients with Jessner's lymphocytic infiltration of the skin (LIS), polymorphous light eruption (PLE), discoid lupus erythematosus (DLE) and sub‐acute cutaneous lupus erythematosus (SCLE) using a large panel of monoclonal antibodies against T cell differentiation antigens (CD3, CD4, CDS), immunoregulatory T cell subsets (CD7, 4B4, 0H4, Leu 8), B cells (CD22), activated cells CD25, OKT9, HLA‐DR), Langerhans cells (CD1) and macrophages (Leu‐M5). The results showed many similarities between LIS and PLE. The most important differences between these conditions and CDLE/SCLE were the high proportions of cells reactive with monoclonal antibody Leu‐8 and the absence of T cells expressing HLA‐DR antigens in LIS and PLE, suggesting absence of local T cell activation in these conditions. The differential diagnostic and pathogenetic aspects of these findings will be discussed.
Desmoplastic trichilemmoma: histologic variant resembling invasive carcinoma
Authors: Hunt S.J. , Kilzer B. , Santa Cruz D.J.
Published: April 2006

A clinical and histologic review of 22 patients (13 males, 9 females) with cutaneous lesions classified as desmoplastic trichilemmoma is reported. Typically, the lesions occur as solitary dome‐shaped papules on the face during (at least) the fifth decade of life. The average age was 64 years (range 19–89) with a median age of 66.5 years. The most frequent clinical diagnosis was basal cell carcinoma, and the most common sites were the lip, eyebrow and nose. Two lesions occurred in examples of nevus sebaceus of Jaddasohn. The proportion of desmoplasia varies, but is generally between 20% to 60% of the lesion. Ulceration is seen in a minority of lesions but when present, is closely associated with underlying desmoplasia. Desmoplasia may be seen in small, as well as large, trichilemmomas; it generally occurs centrally but at times may be seen peripherally. The appearance of strands of epithelial cells entrapped in dense fibrosis and hyalinization may mimic desmoplastic variants of squamous cell carcinoma and basal cell carcinoma. This appearance may be particularly troublesome when the desmoplasia occurs at the base of the biopsy specimen. Knowledge of this phenomenon and the search for more typical features of trichilemmoma such as clear cells and peripherally palisaded columnar cells upon a thickened, eosinophilic basement membrane will allow the correct diagnosis to be made. We believe that the desmoplasia occurs as a secondary change in pre‐existing trichilemmomas.
Cutaneous histopathology of Conradi‐Hunermann syndrome
Authors: Hamaguchi Taizo , Bondar George , Siegfried Elaine , Penneys Neal S.
Published: April 2006

The histopathology of the skin in the ichthyosiform erythroderma associated with classical Conradi‐Hunermann syndrome has been rarely described. Skin biopsies from 2 infants with the classical features of Conradi‐Hunermann syndrome including ichthyosiform erythroderma contained hyperkeratosis, dilated ostia of pilosebaccous structures, and calcium salts in the stratum corneum detectable with special stains. An unusual feature of one case was dilatation of acrosyringeal structures. We hypothesize that dilatation of acrosyringeal structures is analogous to the plugging noted in pilosebaceous units. Taken together, the ichthyosiform erythroderma of Conradi‐Hunermann has a distinctive histologic appearance.
Metaplasia and degeneration in odontogenic cysts in man
Authors: Browne R. M.
Published: April 2006

Abstract. In a histologic study of the walls of 638 odontogenic cysts, the incidence of metaplastic and/or degenerative changes was recorded. There were 402 denial cysts, 81 dentigerous cysts, 15 lateral periodontal cysts, 1 gingival cyst and 139 odontogenic keratocysts.

Mucus cells were present in 39.6 % of the dental cysts, 42.0 % of the dentigeious cysts, 20.0 % of the lateral periodontal cysts and 3.7 % of the odontogenic keratocysts. There was no difference in incidence between the maxilla and mandible. The incidence of mucus cells increased with the age of the patient from whom the cyst was removed. Ciliated cells were present in 0.7 % of the dental cysts and 1.5 % of the odontogenic keratocysts, but were absent from dentigerous cysts and lateral periodontal cysts. Keratin was present in 2.0 % of the dental cysts, 2.5 % of the dentigerous cysts, and all of the odontogenic keratocysts, but was absent from lateral periodontal cysts. Hyaline bodies were present in 6.7 % of the dental cysts, 1.2 % of the dentigerous cysts, none of the lateral periodontal cysts and 9.4 % of the odontogenic keratocysts. Mineralized bodies were present in 2.5 % of the dental cysts, 7.4 % of the dentigerous cysts, 6.7 % of the lateral periodontal cysts and 12.9 % of the odontogenic keratocysts. The origin of these changes is discussed in the light of these findings.
The effect of physical treatment on the induction of heterotopic bone formation by demineralized dentin in guinea pigs
Authors: Bang Gisle , Johannessen Jan Vincents
Published: April 2006

Abstract. A total of 388 allogenic demineralized guinea pig dentin samples, excluding 54 controls, were exposed to ionizing irradiation, ultrasonic vibration, heat, or storage at different temperatures. They were then subjected to amino acid analyses or transmission electron microscopy or implanted in the abdominal muscle of 74 male guinea pigs for four or five weeks. With increasing exposure to irradiation, heat or ultrasonic vibration, there was a decrease in the capacity of the implants to induce bone formation. This was most marked for the implants that had been subjected to 10.0 million rad or high temperature. Implants stored for more than approximately 8–12 weeks seemed to lose some of their bone‐inducing capacity, especially if stored at room temperature. Irradiation and heating resulted in profound changes in the dentin ultrastructure with swelling of the collagen fibrils and loss of cross‐striation. Specimens subjected to ultrasonic vibration showed some cleft formation in the dentin matrix but the collagen fibrils had retained cross‐striation. While irradiation caused a slight increase in acetic acid extractability of the dentin matrix, ultrasonic vibration and heating did not. It is suggested that the bone inducing capacity of dentin matrix is related lo a non‐collagenous protein.
Longitudinal studies in oral leukoplakias
Authors: Bánóczy J. , Sugár L.
Published: April 2006

Abstract. Follow‐up examinations of 520 patients with oral leukoplakia during a 25‐ycar period showed cancer development in 31 cases, i.e. 5.9 %. The mean observation period was 8.7 years. The age distribution of leukoplakia showed that the highest frequency occurred in the age group 51–60 years; carcinoma was most frequency in the age group 61–70 years. Females had a higher prevalence for malignant transformation of oral leukoplakia (7.2 %). The tongue was the site of predilection for malignant transformation (in 38.8 % of the eases). Among etiological factors, smoking, mechanical irritation, alcohol consumption and electrical potential differences could be correlated with oral leukoplakia. Certain factors seemed to favor the development of cancer. Carcinoma originated in 26 % of verrucous leukoplakias and in 74 % of erosive leukoplakias. The highest risk for malignant transformation of leukoplakia occurs in the erosive type, whereby 28 % of all eases developed into cancer.
The application of stereological methods for studying the effects of differing fixative osmolalities on the intercellular space of oral epithelium. II. Inflamed epithelium
Authors: Squier C. A. , Waterhouse J. P. , Kraucunas Eugenia
Published: April 2006

Abstract. The effects on normal and mildly burnt oral epithelium of rat palate of commonly used fixatives differing in osmolality and composition were examined quantitatively by the application of a stereological method at the electron microscope level. With five out of six different fixative solutions the intercellular spaces of the burnt epithelium occupied a significantly larger relative volume than in normal epithelium, and the tissue did not respond in the same way as normal epithelium does to differences in fixative solution. This may reflect changes in tissue properties resulting from burning. The differences in size of intercellular spaces between tissues fixed in different solutions were such that burnt tissue fixed in one solution did not always show larger intercellular spaces than normal tissue fixed in another solution. Observations of the ultrastructural changes of inflammation in oral epithelium should therefore always he checked by observations on identically fixed normal tissue.
The acquired pellicle: Variability and subject‐dependence of specific proteins
Authors: Kraus Frederick W. , ØRstavik Dag , Hurst David C. , Cook Carolyn H.
Published: April 2006

Abstract. By indirect immunofluorescence, 13 different proteins were studied in 2‐hour, acquired pellicles collected from four subjects over a 5‐day period. The 300 specimens were coded, and the intensity of fluorescence specific for each protein was scored by two independent observers.

Statistical analyses indicated that the mean score values differed significantly when a comparison was made between individual proteins or between subject‐donors of the pellicles. Also, the scores for each protein were highly dependent on the subject. Despite daily fluctuations, the pellicles from each subject presented a characteristic protein profile.

Frequently, high fluorescence scores were noted for proteins of generally low salivary concentration, e.g., IgM and IgG. The third component of complement was discovered in several pellicles and, by subsequent testing, in whole saliva but not in parotid fluid. Its presence in pellicles of an edentulous subject suggests that this protein may be transferred across the oral epithelium.
Activity levels of some oxidoreductases of carbohydrate metabolism in leukoplakic and normal human buccal epithelium
Authors: Gerson Stanley , Silverman Sol
Published: April 2006

Abstract. The levels of activity of three oxidoreductases (glyceraldehyde‐3‐phosphate, NAD‐de‐pendent isocitrate, and glueose‐6‐phosphate dehydrogenases) were determined in pathologically keratinized (leukoplakic) and adjacent normal nonkeratinzed epithelium from the buccal mucosa of humans. Samples of histologically identifiable epithelial layers as well as of whole epithelium were isolated by microdissection from frozen‐dried sections and assayed by ultramicrochemical methods. In the leukoplakic epithelium, as compared to the normal, glyceraldehyde‐3‐phosphate dehydrogenase activity was slightly higher, NAD‐dependent isocitrate dehydrogenase activity was more than twice as high, and glucose‐6‐phosphate dehydrogenase activity was about l/3 lower. These findings suggest a higher potential for the formation of energy‐rich compounds but a lower potential for pentose phosphogluconate pathway activity in the leukoplakic epithelium.
Electron microscopic appearance of dentin after decalcification and recalcification in vitro
Authors: DeSteno* C. V. , Feagin F. F.
Published: April 2006

Abstract. Cross‐sections of bovine incisor root dentin, 0.2 mm thick, were decalcified by ethylenediaminetetracetate at pH 7.4. After 2‐day immersion in recalcifying solution (3.75 mM Ca, 1.67 mM P, 22 mM CO3, 155–160 mM NaCl, pH 7.2, and 28°C) the previously decalcified dentin contained 32 % of the calcium phosphate of natural adult bovine dentin. Electron micrographs showed the deposition of minerals in the previously decalcified dentin matrix after immersion in the recalcifying solution. The matrix near the cemental surface appeared recalcified. Globular appearing mineral deposits occurred in the uncalcified matrix. The mineral deposits in the intertubular matrix apparently indicate sites of nucleation.
In vivo calcification of implanted bone cells
Authors: Mckinney Ralph V. , Dirksen Thomas R. , Schuster George S. , Bustos Sergio
Published: April 2006

Abstract. Bone cells raised in cell culture from the osteogenic cells of newborn rat calvaria were reimplanted in the same species of animals from which the cells were derived. The cells were sealed in Teflon rings containing Millipore filters over both ends. Evidence of calcification occurred inside the implanted ring chambers at 118 and 279 days following implantation in vivo. The calcified matrix produced by the cells had a pattern reminiscent of membranous bone production.
Cytological and histological keratinization studies in leukoplakias of the mouth
Authors: Sahiar B. E. , Daftary D. K. , Mehta Fali S.
Published: April 2006

A correlative histocytological study for keratinization was done in 446 cases of oral leukoplakia. Cytologically, keratinization could be correctly identified in 91 % of leukoplakias exhibiting orthokeratosis, 73 % of leukoplakias exhibiting parakeratosis, and 78 % of cases showing both types of keratinization. Cytologically, orthokeratosis was present in 83 % of individuals with homogeneous leukoplakia and in 69 % with ulcerated leukoplakia, while parakeratosis was present in 7 % of homogeneous leukoplakias and in 19 % of ulcerated leukoplakias. A higher frequency of dysplasia was observed in smears and their corresponding histological sections for those cases which had revealed only parakeratosis in the cytological examination and for both orthokeratosis and parakeratosis as compared to those showing only orthokeratosis.

It is suggested that the cytological method is a reliable method for studying oral keratinization and is of value to the clinician in identifying the type of leukoplakias which may need to be biopsied for further surveillance.
Cyclic AMP content of gingival fluid in women taking oral contraceptives
Authors: Grower Marvin F. , Lyon Douglas R. , Levin Marvin P. , Chandler Dorothy W.
Published: April 2006

Gingival fluid samples were collected from 12 healthy adult women who ranged in age from 19 to 34 years. Seven subjects with normal menstrual cycles who received no medications acted as controls while five subjects who had been using oral contraceptives for a minimum of 17 months constituted the experimental group. The women using birth control pills showed a 53% increase in the gingival fluid volume versus the controls. Radioimmunoassay revealed a mean concentration of cyclic adenosine monophosphate (cAMP) in the gingival fluid of 3.8.10−6 M in the controls and 1.9.10−6 M in subjects using oral contraceptives, although the total amount of cAMP present in the fluid from both groups was equal. These gingival fluid cAMP levels were a hundredfold higher than those measured in serum and saliva.
Studies on human dental plaque
Authors: Holt Robert L.
Published: April 2006

Abstract. Human supragingival dental plaque was collected from patients with various degrees of caries and periodontal disease. Plaque extracts, prepared in five different solutions (four varied from pH 1.8 to 12.7; one contained urea), were analyzed by polyacrylamide gel electrophoresis, and tested for amylase and lysozyme enzyme activity. Because no qualitative or quantitative advantages of using the extremes of pH or urea were observed, all subsequent extracts were prepared in phosphate buffered saline at pH 7.3. Concentrated extracts were fractionated by gel filtration and characterized by polyacrylamide gel electrophoresis, peptide mapping, molecular weight estimation, determination of enzymatic activities and amino acid and carbohydrate analyses. Regions of similarity among the gels were revealed by comparing the electrophoretic patterns of pooled plaque extract, normal serum and whole saliva. The elution pattern of pooled plaque extract from a standardized Sephadex G‐200 column indicated the presence of both high and low molecular weight proteins that might have correlated with the components of normal serum and saliva. A predominant and dialyzable third fraction had no correlate in either serum or saliva. The small peptides in this fraction were subjected to amino acid, carbohydrate and peptide map analyses. The most abundant amino acids were alanine, glutamic acid, glycine, valine, leucine, lysine and serine. These small components contained no neutral or amino sugars. Pooled plaque extract and the small peptides exhibited similar peptide maps.
Crystalline structure of salivary calculi
Authors: Anneroth Göran , Magnus Eneroth Carl , Isacsson Göran
Published: April 2006

Abstract. The crystalline substances localized in different areas of salivary calculi were identified by using microradiographic and X‐ray microdiffractometric techniques. All 19 calculi analyzed had a general pattern of apatite which was recognizable both in the center and at varying distances from the core. In addition to apatite patterns, six of the calculi gave a diffraction pattern of whitlockite, which in all but one case was located in the central part of the calculi. The influence of various factors on the distribution of the crystalline substances of apatite and whitlockite within the calculi is discussed.
Ultrastructural observations of the oral mucosa in Anderson‐Fabry disease
Authors: Archard H. O. , Brindley H. P.
Published: April 2006

Abstract. Electron microscopic study of oral mucosa from a patient with Anderson‐Fabry disease (glycosphingolipid lipidosis) revealed lamellar and membranous osmiophilic intra‐cytoplasmic inclusions having a periodicity of 4.5 nanometers. These were observed chiefly in reticulo‐endothelial cells as membrane bound and occasionally unbound bodies. They could also be observed within the cytoplasm of squamous epithelial cells, particularly of the stratum germinativum. Morphologic features in endothelial and epithelial cells are described.
The incidence of focal chronic inflammatory changes in human submandibular salivary glands
Authors: Scott John
Published: April 2006

Abstract. Focal chronic inflammatory changes have been investigated in a series of otherwise non‐diseased submandibular salivary glands obtained at necropsy from 96 subjects evenly divided by sex and decades of adult age. Two types of change were recorded: focal aggregates consisting predominantly of lymphocytes; and limited intralobular areas of parenchymal change similar to those present in obstructive sialadenitis. These were termed focal lymphocytic adenitis and focal obstructive adenitis respectively. For each gland the numbers of foci of each type were separately expressed per unit area of section examined.

Focal lymphocytic adenitis, which was almost universally present throughout the series, in most cases was not associated with destructive changes in the parenchyma. It showed no simple pattern of incidence in relation to age and sex. Focal obstructive adenitis, also frequently present, showed a gradually increasing prevalence with age. Persistent foci of this type tended to form fibrous scars. These were more frequent in older decades. The increasing incidence of obstructive foci throughout adult life, plus in older age groups their persistence as focal scars, both contribute to the gradual reduction in parenchyma which is a feature of aging in the human submandibular gland.
Electron microscopic observations of “keratin pools” in chronic hyperplastic oral mucosa
Authors: Archard H. O. , Denys F. R. , Martinez M. G.
Published: April 2006

Abstract. “Keratin pools,” previously characterized clinically and histochemically in the superficial epithelium of chronic hyperplastic oral mucosa, were studied by light and electron microscopy. These occured as small beaded and larger coalescent masses which varied in metachromasia. Ultrastructurally, the “keratin pools” consisted of electron‐dense, amorphous or finely‐granular material developing and coalescing, chiefly as extracellular deposits. The “pools” frequently possessed a layered arrangement alternating with cells having distinct tonofilaments, desmosomes, and definite cell membranes. Occasional bands of filamentous‐like material, possibly representing tonofilament bundles, were observed in some “pools.”
Studies on the dental lamina as related to its role in the etiology of cysts and tumors
Authors: Stoelinga P. J. W.
Published: April 2006

Abstract. The natural history of the dental lamina involved in the formation of the permanent molars of macaque monkeys is described. Its relation to the oral mucosa and surrounding structures shows that the remnants of this lamina are unlikely to be the principal origin of keratocysts and ameloblastomas.
Changes in vitamin A conditioned hamster cheek pouch epithelium on exposure to commercial shell lime (calcium hydroxide) and tobacco I — Optical histopathology
Authors: Kandarkar S. V. , Sirsat Satyavati M.
Published: April 2006

Abstract Epidemiologically a high incidence of oral cancer and addiction to tobacco, singly or in combination with other ingredients of the betel quid, are closely correlated. Attempts at the induction of malignancy in laboratory animals on exposure to these ingredients have hitherto failed. Studies are reported on cheek pouch epithelium of 152 Syrian golden hamsters exposed to commercial shell lime (calcium hydroxide) and tobacco, singly and in combination, with parallel conditioning by Vitamin A palmitate. The abnormal changes found especially in lime and lime‐plus‐tobacco treated epithelia are massive hyperplasia, keratinization anomalies, marked edema and dysplasia. The most significant findings are (1) greater epithelial alteration caused by lime, lime plus vitamin A, tobacco plus vitamin A, lime plus tobacco and lime plus tobacco and vitamin A, than by tobacco alone; (2) increasing epithelial dysplasia in response to longer periods of exposure to the test substances; and (3) enhancement of tissue changes in the presence of vitamin A.
The Oxytalan Fiber System in the Mandibular Periodontal Ligament of the Lathyritic Mouse
Authors: Sims Milton R.
Published: April 2006

Abstract Experimental lathyrism was produced in young albino mice with a diet containing 50 % sweet pea seed (Lathyrus odoratus). After 7 days on the lathyritic diet, sections of the mandibular molar and incisor periodontal ligaments, when oxidized and treated with aldehyde fuchsin, demonstrated enhanced staining of the oxytalan fibers and numerous vessels. At this time aldehyde fuchsin or orcein also revealed marked pathological changes in the periodontal ligament of all molars. When lathyrism was prolonged for 12 weeks, both the molar and incisor oxytalan systems were still readily identifiable although the molar periodontal ligament continued to he severely affected by lathyrism. The oxytalan fibers retained their characteristic tooth‐vascular association in all of the lathyritic mice. Oxytalan fibers of the lathyritic and control animals showed similar reactions to enzyme digestion with beta‐glucuronidase, elastase, and pepsin. However, gingival elastic fibers reacted in a different way from oxytalan fillers with beta‐glucuronidase and elastase treatment. These findings indicate that in the lathyritic mouse the oxytalan fiber system of functioning teeth possesses a high degree of permanence and is metabolically distinct from collagen and elastic fibers.
Immunopathology of Sjögren‐like* disease in IMZB/NZW mice
Authors: Keyes Gordon G. , Vickers Robert A. , Kersey John H.
Published: April 2006

Abstract In vitro responsiveness of spleen cells from NZB/NZW (B/W) female mice, aged 2 through 40 weeks, to the mitogens phytohemagglutinin (PHA), concanavalin‐A (Con‐A) and lipopolysaccharide (LPS) was determined. An age‐related decline in proliferative response of splenic cells was found; this decline correlated with the age of onset and progression of lymphoid infiltration in lacrimal and salivary glands in the mice. The worsening with age of this lymphoid infiltrate, coupled with the decline in responsiveness to mitogens, suggests a complex immunopathologic process with destruction of glands terminating in a disease similar to the Sjögren syndrome in humans.
Calcification Mechanisms: Roles for Cells and Mineral
Authors: Becker Gerald L.
Published: April 2006

Abstract Recent findings suggest that cellular activity and mineral chemistry have important roles in initiating mineral formation in calcifying tissues. Under biological conditions, hydroxyapatite (HA), the predominant and most stable form of insoluble calcium phosphate, forms only through a more soluble, noncrystalline precursor, amorphous calcium phosphate (ACP). The conversion of ACP to HA can be extensively inhibited by many biologically ubiquitous small ions at their typical tissue concentrations. The earliest mineral deposits in the matrix of several calcifying tissues are associated with tiny membranous vesicles. Intramitochondrial calcium phosphate granules are also seen within intact cells of certain calcifying tissues. Current hypotheses for initial mineral deposition, based on these findings, are reviewed.
The ultrastructure of an oral angiomyoma
Authors: Reichart Peter , Reznik‐Schüller Hildegard
Published: April 2006

A case of an oral angiomyoma is presented. The light‐ and electron‐microscopic features of this rare oral tumor are described and compared to ultrastructural findings in related tumors.
Oral lichen planus:
Authors: Krutchkoff David J. , Cutler Leslie , Laskowski Stella
Published: April 2006

Abstract. A critical review of the literature was undertaken to determine if there is valid data to support the contention that oral lichen planus represents a disease with significant potential for malignant degeneration. Although there are reports alleging such a relationship, there is insufficient documented evidence to state with any degree of confidence that oral lichen planus, in itself, represents a premalignant state.
Calcifying odontogenic cyst with ameloblastic fibro‐odontome: one lesion or two?
Authors: Farman Allan G. , Smith Sydney N. , Nortjeea Christoffel J. , Grotepass Frans W.
Published: April 2006

Abstract. The calcifying odontogenic cyst is unusual in that it is frequently found in conjunction with the histologic features of a variety of other odontogenic conditions. Two cases are reported, one of which contained areas histologically similar to the ameloblastic fibro‐odontome and also showed condensations of cells in the stroma beneath epithelial strands proliferating from the cyst lining. In both cases the “ghost cells” stained strongly for disulphide groups but only occasional areas were positive for sulphydryl groups. No amyloid or “amyloid‐like” material was detected. As no part of the current name is specific to this lesion it is suggested that the nomenclature should be changed – perhaps to “ghost cell cyst”.
Sublingual keratosis and malignant transformation
Authors: Pogrel M. A.
Published: April 2006

Abstract. In a follow‐up study on a small number of cases of sublingual keratosis, a 16% malignant transformation was noted. This confirms recent studies which have pointed out the risk of malignant change in these lesions.
Development of annular gap junctions in guinea pig epithelia
Authors: Archard H. O. , Denys F. R.
Published: April 2006

Abstract. Epithelia from skin, palate, buccal mucosa and dorsal tongue were studied in normal and zinc deficient guinea pigs by transmission electron microscopy. Gap junctions (nexuses) were observed primarily in the basal and prickle cell layers. They were also seen to form bulging and looping configurations which appeared to pinch off into the cytoplasm forming what are recognized as annular gap junctions. These may be attached to the surface or represent separate, intracytoplasmic, nexus‐bound inclusions. Their contents varied, but most often they contained glycogen and ribosomal‐like particles. Various cell organelles were also seen entrapped, most common of which were membrane coating granules. The development of these annular gap junctions is a prominent feature of many epithelia. It has been suggested that they probably serve to maintain a synchronized differentiation throughout the various epithelial layers.
External root resorption following bleaching of pulpless teeth with oxygen peroxide
Authors: Cvek Miomir , Lindvall Ann‐Marie
Published: April 2006

Abstract Eleven teeth in which bleaching with 30% oxygen peroxide was followed by external root resorption are presented. One tooth had no traumatic history, while the others were previously subluxated or luxated in accidental injury. Radiographic appearance of resorptions varied. In 2 teeth the resorptions were only superficial and did not progress during the observation time. In 5 teeth the resorptions were associated with ankylosis. In the remaining 4 teeth the resorption was progressive, bowl‐shaped and associated with radiolucency in the adjacent alveolar bone. It was suggested that damage to the periodontium, caused by oxygen peroxide at the time of treatment, may heal or be followed by ankylosis and, when complicated by bacterial contamination, develop to a progressive root resorption associated with persistent inflammatory changes in periodontal tissues.
Allergenic potential of root canal sealers
Authors: Hensten‐Pettersen Arne , Brstavik Dag , Wennberg Alt
Published: April 2006

Abstract The sensitizing potential of 4 root canal sealers, Endo‐methasone, ProcoSol, AH26, and Kloroperka N‐Ø, was evaluated in a modified guinea pig maximization test. All 4 materials induced sensitivity. When single components of the sealers were used in subsequent skin challenges of the same animals, positive responses were elicited by eugenol and thymol iodide in Endométhasone, eugenol in ProcoSol, epoxy resin in AH26, and chloroform in Kloroperka N‐Ø. As reports on hypersensitivity reactions after endodontic treatment are rare, the demonstrated capability of the sealers to induce a delayed hypersensitivity reaction may seem to be of minor clinical significance. However, a possible allergic reaction should be considered in endodontic patients with complicated postoperative symptoms. Furthermore, the potential for the sealers to cause dermatological problems to the professionals handling them should not be overlooked.
Technical quality of root fillings in an adult Swedish population
Authors: Petersson Kerstin , Petersson Arne , Olsson Berit , Hakansson Jan , Wennberg Alf
Published: April 2006

Abstract The purpose of this investigation was to study the technical quality of root fillings in a sample representative of the Swedish population. The material consisted of radiographs of the mandibular premolar and molar regions from 861 individuals (20–60 years old). Pulpoiomies and root fillings were registered and the periapical status and the technical quality of the root fillings were evaluated. The results showed that more than 60% of the root‐filled teeth were inadequately sealed. The defect most commonly found was incomplete obturation of the root canal. Periapical lesions were observed in 31% of the root‐filled teeth. In teelh with completely obturated root canals, only 7% had a periapical lesion, as compared to 45% of the teeth with inadequately sealed root canals.
Periapical actinomycosis: A follow‐up study of 16 surgically treated cases
Authors: Happonen Risto‐Pekka
Published: April 2006

Abstract Clinical features of 16 immunocytochemically verified and surgically treated cases of periapical actinomycosis were evaluated. A. israelii was demonstrated in 13, A. propionica in 10, and A. naeslundii in 6 biopsy specimens. More than one of these species were present in 9 lesions. All cases had a long and complicated clinical history accompanied by fistulation and destruction of cortical bone plates. During a mean follow‐up period of 28 months after periapical surgery, only 1 clear failure was found. The results indicated that periapical actinomycosis is more common than previously believed and that these infections can be controlled by ordinary periapical surgery.
Non‐invasive recording of blood flow in human dental pulp
Authors: Gazelius Bertil , Olgart Leif , Edwall Björn , Edwall Lennart
Published: April 2006

Abstract Laser Doppler flowmetry was applied to human teeth to study whether blood How in the pulp can be recorded. In sensitive, intact incisors the level of the output signal Ironi the flowmeter was clearly distinguishable from that obtained in adjacent nonsensitive or pulpeetomized teeth. Heart beat synchronous oscillations, which were present in the recording signal from normal teeth, were absent in nonvital teeth. Local injection of lidocaine (20 mg/ml) with adrenaline (12.5 μg/ml) caused a pronounced and long‐lasting reduction of the flowmetric values in healthy teeth. The oscillations were also reduced in amplitude. Repeated recordings showed good reproducibility. Thus, changes in blood (low may be assessed in a tooth by tin's non‐invasive method. The instrument is a promising tool in the clinical evaluation of pulp vitality following traumatic injuries.
Pulpal reactions to glutaraldehyde and paraformaldehyde pulpotomy dressings in monkey primary teeth
Authors: Tagger Etty , Tagger Michael , Sarnat Nairn
Published: April 2006

Abstract Pulpotomy was performed in primary teeth of 4 vervet monkeys to compare the effect of an experimental dressing containing glutaraldehyde (GL) to a similar formula with paraformaldehyde (PF). Forty teeth were examined histologically 2 weeks to 5 months post‐operatively. In the PF group, calcifications were more frequently observed and the central core of tissue in the root canal was heavily laden with debris. Pathologic apical resorption and lesions were more frequent. The pulp in the apical third of the root canal was usually uninflamed in the GL group and peripheral calcifications were seldom observed in it. Reaction to GL seemed, therefore, more favorable clinically. Defects were not observed in the permanent teeth that erupted following shedding or extraction of the experimental primary ones of either group.
Healing capacity of human and monkey dental pulps following experimentally‐induced pulpitis
Authors: Warfvinge Johan , Bergenholtz Gunnar
Published: April 2006

Abstract Intra‐ and extracellular products from oral bacteria were placed in Class V cavities prepared in dentin of human and monkey teeth to compare initial and late pulp tissue reactions. In one set of teeth, the bacterial material was left in the cavities for the entire experimental period (4, 10, 30 d in monkeys, 30 d in humans). In other teeth the challenge was stopped after 32 h and the bacterial material was removed and substituted with zinc‐oxide eugenol cement. The subsequent pulp tissue responses were observed histologically after 4, 10 (monkeys) and 30 d (humans and monkeys). Thirty‐two hours of bacterial challenge to human teeth induced intense acute inflammatory lesions. Four days of challenge in monkeys resulted in severe inflammatory cell involvement and pulpal necroses in a few teeth. At extended periods of observation severe inflammatory lesions were less frequent and the majority of the pulps showed tissue repair and healing at 30 d. This occurred irrespective of experimental protocol. Fourteen of 84 monkey teeth and none of 17 human teeth presented pulp tissue necrosis at follow‐up. Data showed that the‐dental pulp of both young human and monkey teeth can recuperate from a state of suppurative inflammatory involvement. Healing occurred irrespective of whether the bacterial challenge was removed or left in place. Findings also indicated that an acute inflammatory lesion rapidly could result in total pulp tissue necrosis.
Patterns of indirect fracture in intact and restored human premolar teeth
Authors: Salis Sergio G. , Hood James A. A. , Stokes Alastair N. S. , Kirk Ewen E. J.
Published: April 2006

Abstract Fracture patterns of contralateral pairs of intact and restored premolar teeth were determined after dynamic loads of equal energy were applied to the medial aspects of the buccal cusps. The predominant fracture path for intact teeth ran obliquely from the occlusal fissure to the buccal cervical region, followed by fractures from the point of impact. Most teeth restored with MOD amalgams fractured from the base of the cavity, whereas those with amalgam overlays suffered less severe fractures, sited higher in the cusps. When teeth restored with MOD gold overlays and full gold crowns fractured, the site was frequently in the root. The value of cuspal protection by means of overlay techniques was confirmed by this study.
Mechanisms of new attachment formation
Authors: Polson Alan M.
Published: April 2006

Abstract A goal of periodontal therapy is predictable regeneration of a periodontium at the site of a previous marginal periodontitis. Current clinical therapeutic techniques result in repair, and not regeneration with formation of a new connective‐tissue attachment. Investigations have shown that surface demineralization of dentin predisposes toward a new connective‐tissue attachment, and this attachment may take place in an environment lacking periodontal progenitor cell populations. The role of the root surface is considered regarding inhibition and facilitation of these connective tissue responses.
Healing of periapical lesions of pulpless teeth after endodontic treatment with controlled asepsis
Authors: Byström Anders , Happonen Risto‐Pekka , Sjögren Ulf , Sundqvist Göran
Published: April 2006

Abstract Using a careful anaerobic bacteriological technique, bacteria were shown to be eliminated from infected root canals before the endodontic treatment was finished by root filling. Healing of the periapical lesions of the teeth was followed for 2–5 yr. The majority of the 79 lesions healed completely or decreased in size in such a way that they could be expected to heal. In 5 cases there was no or only an insignificant decrease in the size of the lesions. Two of these lesions were shown to contain bacteria of the species Actinomyces or Arachnid. In another case there were dentin chips in the periapical tissue. Periapical lesions which fail to heal in spite of careful bacteriological monitoring of the endodontic treatment may in some cases be due to an establishment of the bacteria outside the root canal in the periapical tissue. In these sites, the bacteria are inaccessible to conventional endodontic treatment.
Extraradicular endodontic infections
Authors: Tronstad Leif , Barnett Frederic , Riso Kenneth , Slots Jorgen
Published: April 2006

Abstract Eight asymptomatic periapical inflammatory lesions which were refractory to conventional endodontic therapy were examined for the presence of bacteria. Access to the periapical lesions was gained using an aseptic surgical technique. Sterile currettes were used to take microbiological samples from the soft tissue lesions and scrapings from the surface of the root tips. Möller's VMGA III transport medium was utilized and the bacteriological samples were processed using a continuous anaerobic technique. Bacterial growth was evident in the samples from all 8 lesions. Two lesions exclusively yielded anaerobic bacteria and 5 lesions were heavily dominated by anaerobes. Black‐pigmented Bacteroides species as well as anaerobic gram–positive rods and cocci were isolated. Staphylococcus epidermidis was recovered from 3 lesions and 2 Actinomyces species were isolated from 1 lesion. Facultative Streptococcus species were rare periapical isolates. Our study clearly showed that anaerobic bacteria are able to survive and maintain an infectious disease process in periapical tissues.
Effect of preservation media on proliferation and collagen biosynthesis of periodontal ligament fibroblasts
Authors: Oikarinen Kyösti S. , Seppā Silja T.
Published: April 2006

Abstract The viability of periodontal ligament (PDL) cells, which are responsible for the production of ligament proteins, is essential for clinical healing of replanted exarticulated teeth. Cultured human PDL fibroblast‐like cells were used to study the effects of various transport media on cell proliferation, collagen synthesis and total protein synthesis. The PDL cells were obtained from intact premolars of a healthy young male patient by trypsinization and scraping the PDL tissue. Proliferation of the cells, the activity of prolyl 4‐hydroxylase, total protein and collagen synthesis were studied after 60 min incubation in Dulbecco's Modified Eagle's Medium (DMEM), milk, saliva and tap water. Proliferation capacity was also investigated after prolonged incubation in milk. The results indicated that milk and saliva were superior to water in maintaining these cell functions, but as the saliva used in this study does not resemble that in the clinical situation, we recommend milk as a temporary storage medium for exarticulated teeth before replantation.