Regulation of immune cells in oral lichen planus.

Oral lichen planus (OLP) is an immunological disease and while it is understood that the T cell subsets, FoxP3(+) Tregs and IL17(+) Th17 cells are involved in immune regulation, little is known about their presence in OLP. The aims of this study were to compare the number of cells expressing FoxP3 or IL-17 in OLP with non-specifically inflamed oral mucosa and to determine which cell types expressed FoxP3 and/or IL-17 and their distribution. Immunohistochemistry was used to investigate the presence of FoxP3(+) or IL-17(+) cells in 12 control cases and 17 cases of OLP. These results were analysed quantitatively and qualitatively. Double-labelling immunofluorescence (IF) was used to determine the type of cell expressing FoxP3/IL-17 and these results were analysed qualitatively. OLP displayed significantly more FoxP3(+) cells (mean 79.3 vs. 20.6 cells/defined area, p < 0.0001) and fewer IL-17(+) cells (mean 1.05 vs. 3.30 cells/defined area, p = 0.0003) than non-specific inflammatory cases. The majority of FoxP3(+) cells were in the sub-epithelial infiltrate, while IL-17(+) cells were deeper in the stromal tissues. IF showed that FoxP3(+) cells co-localised with T cells, while the IL-17(+) cells did not. These results show that the balance between Tregs and IL-17(+) cells is altered in OLP, thus supporting the proposition that disturbance in local immune regulation is important in the pathogenesis of OLP. The observation that the IL-17(+) cells were mast cells has not previously been reported in OLP and again raises questions about the role of mast cells in this condition.

Silver solder "tattoo," a novel form of oral pigmentation identified with the use of field emission scanning electron microscopy and electron dispersive spectrography.

OBJECTIVE: The aim of this study was to investigate the use of field emission scanning electron microscopy and electron dispersive spectrography (SEM-EDS) to identify silver solder "tattoo." STUDY DESIGN: SEM-EDS was used to analyze material present in the connective tissue of a patient who presented with bilateral pigmentation of the mandibular lingual gingiva adjacent to the first molars. No dental restorations were present. RESULTS: SEM-EDS analysis identified silver, with no evidence of tin, copper, or mercury. The patient was wearing an orthodontic appliance where brackets had been soldered to the archwire with silver solder. It is hypothesed that the solder underwent electrolytic corrosion with subsequent regrouping of silver ions in the submucosa leading to blue-gray discoloration. CONCLUSION: Spectrography proved to be a powerful diagnostic tool in identifying the metal within the oral mucosa. Attention is drawn to this newly described lesion, which should be included as a differential diagnosis for pigmented oral mucosal lesions.

The development of an ePortfolio for life-long reflective learning and auditable professional certification.

Recent legislative changes, that affect all healthcare practitioners in New Zealand, have resulted in mandatory audits of practitioners who are now required to provide evidence of competence and continued professional development in the form of a professional portfolio. These changes were the motivation for our development of an electronic portfolio (ePortfolio) suitable for both undergraduate and life-long learning. Bachelor of Oral Health (BOH) students, studying to qualify as Dental Hygienists and Dental Therapists, and BOH teaching staff (who held registrations in Dental Hygiene, Dental Therapy and Dentistry) trialled the use of a personal ePortfolio for advancing their academic and professional development. The ePortfolio enables BOH students to collect evidence of their achievements and personal reflections throughout their 3 years of undergraduate study, culminating in registration and the award of an Annual Practising Certificate (APC). The ePortfolio was designed to allow users to store information and then select appropriate material to be displayed or published, thus assisting health practitioners to present high-quality evidence of their participation and achievements, and to meet the professional requirements for their APC.

5-Fluorouracil induces autophagic degeneration in rat oral keratinocytes.

In this study, we investigated the effect of 5-fluorouracil (5-FU) on the keratinocytes of oral epithelium. Female Lewis rats were given 5-FU i.v. and were killed 12, 24 or 36 h after injection. The buccal mucosa was dissected. The number of nuclei with DNA strand breaks and the total number of nuclei per volume of the epithelial basal cell layer was estimated using terminal deoxynucleotidyl transferase (TdT)-mediated deoxyuridine triphosphate (dUTP)-biotin nick end labeling. Epithelial cells were analysed by flow cytometry, transmission electron microscopy and a dye exclusion test. The number of cells with DNA strand breaks increased in 5-FU treated rats. Flow cytometry showed a decrease in cell size and an increase in granularity with increasing doses of 5-FU. Dye exclusion gave no indication of degenerate cell membranes. By transmission electron microscopy, the cells showed evidence of degeneration, shrinkage and loss of cell-to-cell contact. Vacuolation was extensive and, in contrast to apoptotic cells, nuclear chromatin condensation seemed to occur centrally in the nuclei. The results show that 5-FU treatment in vivo induces alterations in rat oral keratinocytes that are consistent with autophagic degeneration.

Inflammatory myofibroblastic tumour of the breast: report of a case with giant vacuolated cells.

Inflammatory myofibroblastic tumours (IMTs) or inflammatory pseudo-tumours are uncommon lesions of unknown aetiology. The majority of the cases are reported in the lungs of young patients. Extra-pulmonary anatomic locations include the abdomen and pelvis, but rare cases have been described in the breast. We describe an IMT in an 86-year-old female, presenting as a well-circumscribed palpable mass in the left breast. Histologically the remarkable feature was the presence of giant vacuolated cells intermixed with spindle cells and a prominent plasma cell infiltrate immersed in a fibrous hyalinized stroma. Immunohistochemical and electron microscopy studies demonstrated the myofibroblastic nature of the giant vacuolated cells and the spindle cells, and the polyclonal nature of the plasma cells. The morphologic and immunohistochemical findings supported the diagnosis of IMT. The biological behaviour of IMT in this age group is unknown and surgical excision with close mammographic follow-up is considered to be appropriate treatment for this lesion in the breast.

Odontoblast differentiation: a response to environmental calcium?

The response of the dental pulp to calcium hydroxide has been well described but the process of pulpal repair leading to dentinal bridge formation appears complex and the mechanisms remain incompletely understood. Through the precise regulation of the free calcium ion in the cytosol, cells have been able to utilize anions such as phosphates for a wide range of activities such as energy production (oxidative phosphorylation). As anions are abundant in the cytosol, intracellular levels of calcium ions are kept low, several orders of magnitude less than that of the surrounding extracellular matrix. Consequently, cells are able to use calcium ions for the regulation of many cellular events. The binding of extracellular molecules such as cytokines, hormones or antibodies, with receptors on the plasma membrane may result in short- or long-term modifications to cellular metabolism, including the mechanisms of intracellular calcium homeostasis. Cell survival depends upon the ability to adapt to changes in the cell's micro-environment. Adaptation in turn results in altered cellular activity that may be interpreted as showing that the cell has become more or less specialised. In some instances this may include the resumption of mitotic activity. If the rate or magnitude of change exceeds a cell's adaptive capacity, the cell dies. Responses of cells to alterations in their environment are reviewed as they may provide an explanation for the success of calcium hydroxide in facilitating pulpal repair and the differentiation of odontoblasts.

A slow release calcium delivery system for the study of reparative dentine formation.

Several liquid, semi-solid and solid delivery systems were formulated and tested to devise a method of reproducibly administering accurate micro-doses of calcium into a 700 microns diameter cavity in a rat maxillary incisor tooth, in the absence of hydroxyl ions. Development of this delivery system was necessary to facilitate studies of the mechanisms of pulpal repair and odontoblast differentiation. The principal requirements for the delivery system were that it should be easily administered into a small pulp exposure in the rat incisor and that a greater than 1000-fold range in calcium ion concentrations could be incorporated and delivered for a period of 2-3 days, preferably in an acidic environment to minimize the effect of non-specific nucleation under alkaline conditions. Poly- (ethylene) glycol microspheres were found to be an ideal vehicle. Under the in vitro dissolution conditions used, complete release of all calcium salts occurred within 12-15 hours, except for the very water-insoluble calcium stearate. It was anticipated that the release of calcium ions would be significantly more prolonged in vivo because of the physical constraints of the prepared cavity as well as the restricted access to fluid flow.

A study of transposed canines in a sample of orthodontic patients.

Tooth transposition is a positional interchange of two adjacent teeth. The most commonly transposed tooth is the permanent canine with either the first premolar or lateral incisor. The records of 54 subjects with transposed canines, both maxillary and mandibular, were collected. Pretreatment study models of these subjects were matched with a similar number of models from unaffected individuals. Bucco-lingual and mesio-distal tooth widths, arch depth and arch width were measured on each model. Thirty-four subjects (63 per cent) were female. Thirty-seven (68.5 per cent) of the cases involved the maxillary arch and thirty-three (89.2 per cent) of these upper arch transpositions were of the canine and first premolar. In cases involving the lower arch the canine was invariably transposed with the lateral incisor. Peg-shaped lateral incisors, supernumerary and/or congenitally absent teeth occurred in 19 subjects. There were some small, but significant differences in the dimensions of some teeth, however there were no statistically significant differences in arch depths, arch widths and most tooth dimensions in subjects with and without transposed canines. These factors do not appear to be related to the development of canine transposition.

In vitro characterization of poly(ethylene) glycol calcium citrate microspheres as a delivery system for the study of reparative dentinogenesis.

The characterization of poly(ethylene) glycol calcium citrate microspheres is described. The calcium content and content uniformity of microspheres, prepared at five concentrations ranging from 46.56 micrograms/g to 81.49 mg/g, were determined by spectroscopy. Under sink conditions first-order in vitro dissolution kinetics were observed. Granules containing approximately 80 mg Ca++/g PEG gave an in vitro calcium release over a 3-day period similar to that of a calcium hydroxide product, Pulpdent.

The effect of transforming growth factor beta one (TGF-beta 1) on wound healing, with or without barrier membranes, in a Class II furcation defect in sheep.

The purpose of this study was to analyse the effect of TFG-beta 1 on wound healing in standardized Class II furcation defects of 48 mandibular second premolar teeth in 24 sheep. The experimental design included a control group (carrier only, 25% pluronic F-127), and 2 experimental groups: group A (80 micrograms/ml TGF-beta 1 + carrier) and group B (80 micrograms/ml TGF-beta 1 + carrier covered with a barrier membrane). Sheep were killed either 2 wk or 6 wk after surgery. Mesiodistal sections of the decalcified specimens were quantified histologically using stereology. Percentage volumes of regenerated bone, fibrous connective tissue and cementum were calculated for each furcation defect. Mean values were analysed using multiple ANOVA; p values were calculated using paired and unpaired Student's t-tests. After 2 wk there was more bone in group B than either of the other 2 groups, but this was not statistically significant. By 6 wk more bone was present in group A than in the control group (p < 0.02) and also in group B when compared with both group A and the control group (p < 0.02 and p < 0.44), respectively. In the 4 wk between sampling significantly more bone had formed (group A < 0.05 and group B p < 0.003, respectively). A negative correlation existed between volumes of bone and fibrous connective tissue and no significant differences between the volumes of cementum were evident between any of the groups. This study demonstrated that TGF-beta 1 encouraged bone regeneration in Class II furcation defects in sheep, an effect enhanced by the presence of a barrier membrane. This is the first report on the use of TGF-beta 1 in conjunction with GTR in periodontal defects.

Regulation and pH-dependent expression of a bilaterally truncated yeast plasma membrane H+-ATPase.

Constitutive, chromosomal expression of yeast pma1 deletion alleles in Saccharomyces cerevisiae yielded functional, truncated forms of the plasma membrane H+-ATPase which were independently capable of supporting wild type yeast growth rates. Deletion of 27 amino-terminal residues affected neither the enzyme's activity nor its responsiveness to changes in glucose metabolism. By contrast, removal of 18 carboxy-terminal amino acids produced an enzyme with a Vmax that was relatively insensitive to glucose-dependent metabolic status and with a Km that was significantly lower than that of the wild type enzyme. These effects were exaggerated when the amino- and carboxy-terminal deletions were combined in a bilaterally truncated H+-ATPase, suggesting that the amino terminus may have a subtle role in modulating ATPase activity. In pma1DeltaDelta cells cultured at pH 6, plasma membrane H+-ATPase levels were much lower than those in cells expressing a wild type ATPase. Increased expression levels could be achieved by growing the pma1DeltaDelta mutant at pH 3, a result that was at least partially due to a sustained, elevated transcription of pma1DeltaDelta mRNA. Our observations suggest that intracellular proton balance can be maintained by regulation of the activity and/or quantity of H+-ATPase in the plasma membrane.

A comparison of stereological and computer-assisted histomorphometric analysis as tools for histological quantification in regenerative studies.

This study was designed to compare computer-assisted histomorphometric analysis (CAHA) and stereology (STER) as measurement tools for evaluating the repair response during periodontal wound healing. Thirty-six histological sections derived from 4 surgically created defects in the furcation of mandibular second premolars of sheep were measured by each technique to determine the furcation area and volume, and the percentage of new bone formation at 7 wk postoperatively. Slides were viewed in random order with the source unknown to the examiner (JL). One section from each of the 4 specimens was flagged for triplicate measurement by each technique. Intraexaminer error was determined to be low as the coefficient of variation in each of the 2 techniques was between 1% and 4%. A consistently higher percentage of bone was identified using stereology. The coefficient of agreement was plotted to determine how closely these 2 techniques were matched in their respective estimations of bone fill in a furcation defect. This analysis revealed statistical bias between the 2-techniques and a low degree of agreement between them. This study demonstrates that the 2 techniques are not interchangeable. It also emphasizes that the reader must be cautious when comparing results from studies in which different systems of measurement and analysis have been used. Stereology was determined to be the measurement tool of choice due to its high degree of reproducibility, ease of use and efficient use of time.

Functional complementation between transmembrane loops of Saccharomyces cerevisiae and Candida albicans plasma membrane H(+)-ATPases.

Saccharomyces cerevisiae PMA1 sequences encoding a putative antifungal target site comprising transmembrane loops 1 + 2 and/or 3 + 4 were replaced with the homologous sequences from Candida albicans PMA1 by using PCR-mediated domain transfer. The chimeric pma1 mutants and an isogenic wild type S. cerevisiae strain had similar growth rates, growth yields, glucose-dependent proton pumping rates, acid-activated omeprazole sensitivities, salt tolerances and antifungal sensitivities. The yields and kinetic properties of H(+)-ATPases in plasma membranes of mutant and wild type strains were comparable. Single heterologous transmembrane loops caused deleterious phenotypes at low pH and elevated temperature. Inclusion of both heterologous transmembrane loops fully suppressed the temperature sensitivity caused by heterologous transmembrane loop 1 + 2, partially suppressed the pH sensitivity and gave Candida-like in vitro sensitivity to vanadate, suggesting that the loops operate as a domain. The fully functional chimeric H(+)-ATPase containing C. albicans transmembrane loops 1 + 2 and 3 + 4 demonstrates this domain's complementarity to the equivalent region of the S. cerevisiae enzyme and validates the wild type S. cerevisiae H(+)-ATPase as an antifungal screening target.

The mechanism of tooth eruption.

Tooth eruption is an essential process for the survival of many different species and although the movement of teeth into function has been the subject of extensive research there is no consensus as to the mechanisms involved. Recent understanding of the mechanisms of cell activation and regulation has widened the scope for further research at the molecular level. This paper reviews the evidence for an eruptive force, its direction and source. The relationships between the eruptive force and molecular mechanisms of cell activation remain to be determined.

Targeting the fungal plasma membrane proton pump.

The need for new mechanistic classes of broad spectrum antifungal agents has prompted development of the membrane sector and ectodomain of the plasma membrane proton pumping ATPase as an antifungal target. The fungal proton pump is a highly abundant, essential enzyme in Saccharomyces cerevisiae. It belongs to the family of P-type ATPases, a class of enzymes that includes the Na+,K(+)-ATPase and the gastric H+,K(+)-ATPase. These enzymes are cell surface therapeutic targets for the cardiac glycosides and several anti-ulcer drugs, respectively. The effects of acid-activated omeprazole show that extensive inhibition of the S. cerevisiae ATPase is fungicidal. Fungal proton pumps possess elements within their transmembrane loops that distinguish them from other P-type ATPases. These loops, such as the conformationally sensitive transmembrane loop 1+2, can attenuate the activity of the enzyme. Expression in S. cerevisiae of fully functional chimeric ATPases that contain a foreign target comprising transmembrane loops 1+2 and/or 3+4 from the fungal pathogen Candida albicans suggests that these loops operate as a domain. The chimera containing C. albicans transmembrane loops 1+2 and 3+4 provides a prototype for mutational analysis of the target region and the screening of inhibitors directed against opportunistic fungal pathogens. Panels of mutants with modified ATPase regulation or with altered cell surface cysteine residues are also described. Information about the ATPase membrane sector and ectodomain has been integrated into a model of this region.

Lymphoglandular bodies in fine-needle aspiration cytology smears.

Lymphoglandular bodies (hyaline bodies or lymphoid globules), when found in cytology smears from fine-needle aspirates, have long been accepted as being diagnostic of lymphoid tissue. To investigate the validity of this association as it relates to malignant tumors, we examined cytologic smears from 132 fine-needle aspirates of malignant neoplasms. Three experienced observers independently scored Diff-Quik-stained smears as to cellularity and number and size of lymphoglandular bodies. Discrepancies were resolved by consensus. Results of the fine-needle aspiration biopsies revealed 6 of 104 nonlymphoid malignancies with easily identifiable lymphoglandular bodies (defined as > 2 lymphoglandular bodies per high-power field) and 3 with numerous lymphoglandular bodies (> 10 per high-power field). These tumors consisted of two cases of small-cell carcinoma, four non-small-cell carcinomas, one ganglioneuroblastoma, one melanoma, and one seminoma. The tumors had few, if any, lymphocytes. Of the 28 lymphomas, 5 had easily identifiable lymphoglandular bodies and 19 had numerous lymphoglandular bodies. Although lymphoglandular bodies in the background of cytologic smears taken from malignant tumors are useful in alerting the pathologist to the possibility of lymphoma, there are exceptions.

Mucus-producing adenopapillary carcinoma of the oral cavity.

Mucus-producing adenopapillary carcinoma is a rare neoplasm of the oral cavity. The literature is reviewed and a case described, with histological and ultrastructural findings of a tumour which involved the upper lip and recurred following local excision.

Immunohistochemical localisation of substance P in human parotid gland.

Based on the clinical observation that pain is experienced during parotid gland surgery under local anaesthesia, the presence of the sensory neuropeptide substance P (SP) was sought. Using a polyclonal antibody, the presence of SP was demonstrated by an indirect immunofluorescence technique, with rat parotid gland and spinal cord serving as controls. SP-containing neuronal elements occurred around acini, blood vessels and ducts. It is suggested that some of the SP-immunoreactive elements are the unmyelinated and thinly myelinated small diameter (A delta and C) fibres, which are regarded as the peripheral receptors for nociceptive information.