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Biomedical subjects

E W Odell

Publications and source records attributed to E W Odell.

At least 19 recordsLinked to original sources

Basal cell adenocarcinoma in minor salivary glands.

Basal cell adenocarcinoma is a rare and relatively recently characterized malignant salivary gland tumour, the malignant counterpart of basal cell adenoma. Diagnosis depends on finding features similar to adenoma but with an infiltrative growth pattern and exclusion of adenoid cystic carcinoma, sialoblastoma and basaloid squamous carcinoma. Basal cell adenocarcinoma is very rarely reported in minor salivary glands. We report three cases of basal cell adenocarcinoma affecting the labial, buccal and palatal minor salivary glands. One recurred following complete removal but with lesional disruption and further local wide excision appeared curative. A further lesion failed to recur in 5 years' follow-up despite marginal excision and a third after 3 years' follow-up. Basal cell adenocarcinoma is considered a low-grade malignancy, and in the minor glands wide excision and radiotherapy are recommended. However, the reported lesions appear to have a more indolent behaviour than previously reported lesions in minor glands.

Adenocarcinoma↗

Expression of ICAM-1 and E-selectin in gingival tissues of smokers and non-smokers with periodontitis.

BACKGROUND: Tobacco smoking affects systemic concentrations of soluble intercellular adhesion molecule (ICAM)-1, but its effect on local expression of adhesion molecules in gingival tissue has not been studied previously. METHODS: E-selectin and ICAM-1 expression on small blood vessel endothelia in gingival biopsies obtained from smokers (n=17) and non-smokers (n=17) with periodontitis was examined with immunohistochemistry. Blood vessels were identified with monoclonal antibody for von Willebrand's factor. RESULTS: A significantly larger number of vessels were observed in inflamed tissues of non-smokers than smokers (P<0.05). The number and proportion of vessels expressing both ICAM-1 and E-selectin was greater in sites with inflammation compared to non-inflamed sites in both smokers and non-smokers (P<0.05). The proportion of the total number of vessels expressing ICAM-1 in non-inflamed sites was greater in non-smokers compared with smokers (P<0.05). CONCLUSIONS: These results suggest that the inflammatory response in smokers with periodontitis may not be accompanied by an equivalent increase in vascularity. Reduced ICAM-1 expression in non-inflamed areas of smokers could reflect a systemic effect of tobacco smoking on ICAM-1 independent of inflammation.

Adult↗

Participating dentists' assessment of the pilot regional online videoconferencing in dentistry (PROVIDENT) project.

OBJECTIVE: To assess the educational effectiveness of delivering continuing professional education (CPE) from dental schools to small groups of dentists at distant sites via videoconferenced links using relatively inexpensive equipment and ISDN2 links. DESIGN: 41 videoconferences between the four campuses of London Dental Schools and postgraduate centres in South East England were assessed using a pre-piloted questionnaire which contained open and specific questions. The questionnaire was given to all participants at the end of each videoconference. Answers to the specific questions were graded using the Likert scale. RESULTS: 40 of the 41 videoconferences were completed satisfactorily and were attended by 257 participants, all of whom completed questionnaires. However, no individual question was answered by all the participants. Of the responses 90% were positive on the topics of appropriateness of the teaching material for delivery by videoconference and of its educational level. 90% of responses also indicated a wish to attend further videoconferences and satisfaction at avoiding the need to travel to London for similar educational activity. 87% rated the lecturers as good or excellent in their use of the medium. 85% of responses indicated that the question and answer sessions within the videoconferences were useful and 82% that the visual aids enhanced the sessions. The technical aspects of the videoconferences were rated positively but to a lesser extent than the educational aspects with 69% of positive responses for visibility of visual aids, 54% for sound quality and 76% for the lecturers use of the technology. The technical aspects of the videoconferences improved during the pilot study. In response to the open questions, participants stated that they found the most useful aspects of the videoconferences were not having to travel, access to first rate lecturers, the discussions and the opportunity to interact with experts. CONCLUSIONS: The participants in this pilot study were positive about the use of videoconferencing to deliver educational material from dental schools to small groups. Once the technology has improved, this medium has the potential to provide CPE for dentists at work or at home in response to their specific needs.

Education, Dental, Continuing↗

A study of videoconferencing for postgraduate continuing education in dentistry in the UK--the teachers' view.

Videoconferencing is an established method for providing medical education over long distances. Our aims were to assess the feasibility of videoconferencing in dental postgraduate education, to evaluate its practicability, teacher satisfaction and evaluate equipment. Twenty-seven teachers from the 4 London Dental Schools provided 41 postgraduate dental education sessions on a range of topics to regional postgraduate centres and dental practices as part of the Thames Health Region's programme. Videoconferencing was carried out using a relatively inexpensive personal computer system link using ISDN2 telephone lines and Z350 protocol. Presenter views and assessment were obtained by questionnaire, interview and videotape. Teachers felt that minimal additional preparation time was required for videoconferencing and 21/27 preferred it to in-person teaching, most noting the saving in travel time. Only 3 of the teachers were dissatisfied with their ability to communicate, 4 were equivocal and 20 were either pleased or very pleased. The teachers largely enjoyed the experience and performed well in the new medium. However, sound quality proved inadequate in 5/41 links and most sessions included some periods of suboptimal sound. Only 4 teachers were satisfied with their ability to perform question and answer interaction with the audience. We conclude that experienced teachers adapt readily to videoconferencing and learn to communicate effectively very quickly. Teachers were positive about the medium despite its shortcomings and improvements in sound quality would allow a rapid expansion of postgraduate dental education by videoconference.

Attitude of Health Personnel↗

Cystic and glial mixed hamartoma of the tongue.

Choristomas and mixed hamartomas of the oral cavity are uncommon lesions that show a variety of clinical presentations, histological appearances and growth patterns. We report a case of an unusual mixed hamartoma of the posterior tongue composed of dermoid cyst, sebaceous and glial elements. Magnetic resonance imaging indicated a predominantly cystic lesion limited to the pharyngeal and posterior part of the anterior tongue. A conservative approach was adopted and the lesion has shown minimal growth for 2 years following diagnosis.

Child, Preschool↗

Rapid growth of giant cell granuloma in pregnancy treated with calcitonin.

The giant cell granuloma of the jaws is a benign osteolytic lesion that may be treated by curettage, intralesional corticosteroids, or calcitonin. These medical treatments may be particularly useful when lesions arise in the immature facial skeleton, recur, or enlarge very rapidly-the last two situations being recognized complications of pregnancy. In this study, a patient is presented with a central giant cell lesion of the maxilla that switched from a relatively indolent growth pattern to become a rapidly enlarging and destructive lesion in the maxilla almost immediately after the patient became pregnant. Although calcitonin treatment is normally avoided in pregnancy, it proved highly effective, caused no obstetric or fetal side effects, and was not contraindicated by renal failure due to lupus nephritis. Histologically, the lesion was converted to a fibro-osseous lesion-like appearance. On the basis of the results of this case, calcitonin appears to be a safe, effective, and conservative treatment for giant cell granulomas that enlarge rapidly during pregnancy.

Adult↗

Characterization of CD44 splicing patterns in normal keratinocytes, dysplastic and squamous carcinoma cell lines.

The CD44 glycoprotein is spliced from a complex gene of 10 constitutive and 10 variant exons. In this study, CD44 splicing patterns and intron 9 retention were investigated by exon-specific RT-PCR for variant exons v1-v10 and intron 9 in normal, immortalized, dysplastic and malignant keratinocytes. Expression of product was determined immunohistochemically for some of the exons. Normal keratinocytes showed one major transcript including exons v2-v10 and 3 minor transcripts. No lines showed a normal CD44 splicing pattern but rather a variety of truncated transcripts of contiguous variant exons which overall correlated with expression. Squamous cell carcinoma (SCC)-4 and SCC-9 lines showed relatively normal transcripts although protein was expressed only by SCC-9. SCC-12B2, SCC-15, SCC-25 and SCC-27 showed a series of shorter overlapping transcripts, with loss of exons v8-v10 in the major transcripts. Intron 9 was not retained in normal keratinocytes or cell lines. Despite the fact that keratinocytes constitutively express all variant exons, splicing patterns are distinctly abnormal and merit investigation as potential markers for epidermal and oral squamous malignancy.

Carcinoma, Squamous Cell↗

Expression of E-cadherin, cellular differentiation and polarity in epithelial salivary neoplasms.

To investigate whether expression of E-cadherin correlates with polarised tissue organisation, grade or tumour type in salivary neoplasms, frozen sections from 30 salivary gland neoplasms were stained immunohistochemically for E-cadherin using the antibody HECD-1 and compared to the staining patterns in five samples of normal salivary gland. Lesions with areas of lack of staining were restained at two higher antibody concentrations. Normal salivary gland stained strongly around the periphery of acinar and ductal cells. Neoplasms mostly stained strongly regardless of neoplasm type. Reproducible loss of expression was found only in epithelial cells showing stromal or plasmacytoid (hyaline) differentiation in pleomorphic adenoma. Low- and high- grade mucoepidermoid carcinomas, adenocarcinoma NOS and carcinoma ex pleomorphic adenoma showed focal loss of expression but this was not related to tissue architecture, differentiation or invasiveness. We conclude that the relationship seen between E-cadherin expression and cell polarity/glandular organisation in breast and colon does not appear to exist for salivary gland neoplasms in which the diversity of architectural patterns precludes detection of any simple relationship. E-cadherin expression seems unlikely to be a useful marker for diagnosis or prognosis in salivary neoplasia in general.

Biomarkers, Tumor↗

Plasma concentrations of reputed tumor-associated soluble CD44 isoforms (v5 and v6) in smokers are dose related and decline on smoking cessation.

There is some evidence to suggest that smoking may affect circulating levels of CD44 (sCD44) molecules. Therefore, we investigated the effect of smoking on the circulating level of sCD44 by comparing the change in total sCD44, sCD44v5, and sCD44v6 concentrations over 1 year in a group of people who quit smoking (n = 30) and a control group of people who continued to smoke (n = 30). Smoking status and compliance were monitored by analysis of plasma cotinine and expired CO levels and also by self-reported tobacco use. We show a dose-dependent relationship between smoke intake and baseline plasma concentrations of reputed tumor-associated CD44 variant isoforms (sCD44v5 and sCD44v6) in smokers (n = 60). There was a significant decline in the level of both sCD44v5 and sCD44v6 in quitters as compared with continuing smokers [-13.2 (95% confidence interval, -7.6 to -18.8; P < 0.001) and -62.2 ng/ml (95% confidence interval, -33.9 to -90.6; P < 0.001), respectively], but not in the total sCD44 concentration. These results show that the increased concentrations of sCD44v5 and sCD44v6 in smokers are dose related and reversible and suggest that the attributed diagnostic specificity and prognostic value of sCD44 molecules in malignant and inflammatory disease may be affected by smoking status.

Adult↗

Quantitative assessment of apoptosis in oral lichen planus.

OBJECTIVE: The aims of this study were to examine the frequency of apoptoses in oral lichen planus by in situ end labeling, to ascertain whether this technique is as sensitive as conventional histologic analysis, and to examine the effect of lymphocytic infiltration. STUDY DESIGN: Numbers of apoptoses in hematoxylin-eosin stained sections were compared with numbers of apoptotic nuclei identified by in situ end labeling in oral lichen planus (n = 26) and normal buccal epithelium (n = 8). Immunohistochemical staining with MIB-1 and for Bcl-2 and Bax enabled possible regulatory pathways to be investigated. RESULTS: In oral lichen planus, approximately 1 apoptotic cell was detected per millimeter of basal layer, cell death increasing with lymphocytic infiltration. Epithelial cell proliferation did not correlate with apoptosis. Bcl-2 expression was weak or absent in basal cells, and Bax was localized to upper prickle cells. CONCLUSIONS: Increased numbers of apoptoses were detected in oral lichen planus, especially in association with lymphocytic infiltration, higher numbers being seen with hematoxylin-eosin staining than with in situ end labeling.

Antigens, Nuclear↗

Pyostomatitis vegetans associated with asymptomatic ulcerative colitis: a case report.

Pyostomatitis vegetans, a rare pustular disorder of the oral mucosa, is a highly specific marker for inflammatory bowel disease and may be difficult to treat. A case of pyostomatitis vegetans in a patient with long-standing asymptomatic ulcerative colitis is presented. Complete remission was achieved with topical steroids; no systemic treatment was required.

Administration, Topical↗

A case of metastasizing pleomorphic adenoma.

The pleomorphic adenoma is the most common benign salivary neoplasm. A case is presented in which a palatal pleomorphic adenoma seeded a metastasis in the medullary cavity of the anterior maxilla, apparently by hematogenous spread after surgical manipulation.

Adenoma, Pleomorphic↗

Potential mechanisms of susceptibility to periodontitis in tobacco smokers.

Tobacco smoking is probably the most important, controllable environmental risk factor in periodontitis. It results in changes in the vascular, inflammatory, immune and healing responses. The degree of exposure to tobacco smoking can be measured in pack years or by measuring serum cotinine and nicotine levels. In a previous paper we reported elevated levels of serum soluble intercellular adhesion molecule-1 (sICAM-1) in smokers, regardless of periodontal status. Elevated sICAM-1 has been found to be a risk marker for cardiovascular disease. In the present paper we report the short-term effects of an episode of smoking on blood flow and levels of sICAM-1. Human volunteers included non-smokers, light smokers and heavy smokers. Relative blood flow was monitored in the gingivae and forehead skin using a laser Doppler flowmeter and serum levels of sICAM-1, cotinine and nicotine measured before during and up to 60 min following an episode of smoking. We could not provide evidence to support the theory that there is localized vasoconstriction within the gingival tissues. In contrast, there was a significant increase in blood flow in the forehead skin of light smokers which was not observed in non-smoking controls or in heavy smokers, suggesting a long-term tolerance in this latter group. The level of sICAM-1 remained unchanged during this episode, further suggesting a long-term effect. In a parallel group of subjects, we were able to demonstrate a direct significant correlation between sICAM and serum cotinine levels. These observations may be relevant to aetiological mechanisms in periodontitis and other smoking-associated diseases.

Cotinine↗

Gingival fibromatosis with prune-belly syndrome.

A case is described in which a child appeared for evaluation with marked gingival overgrowth, facial dysmorphism, and abdominal defects consistent with prune-belly syndrome. The relationship between this case and other reports of gingival enlargement are discussed. Coincidence of the oral, facial, and abdominal abnormalities has not been previously reported.

Child, Preschool↗

Minor salivary gland hyalinisation and amyloidosis in low-grade lymphoma of MALT.

Two patients with low-grade lymphoma of mucosa-associated lymphoid tissue (MALT) arising in primary Sjögren's syndrome developed solitary nodules in their lips. Histologically both lesions showed enlargement and hyalinisation of single minor salivary glands with acinar atrophy, loss of most ducts and conversion into almost acellular sclerotic eosinophilic masses. In one case the lesion was shown to contain an amyloid component. No amyloid was detected in the second case but deposition of collagen and basement membrane and sclerotic neoplasm were excluded.

Amyloid↗

Expression of CD44 variant exons by primary and metastatic oral squamous carcinomas.

Abnormal CD44 expression in many neoplasms correlates with behaviour, but reports on its role in oral squamous carcinoma are contradictory. CD44 expression was characterised in a closely matched series of oral carcinomas with and without metastases in both frozen and formalin-fixed tissue and correlated with behaviour and histological grading parameters. Eleven primary oral squamous carcinomas without metastases and nine primary carcinomas with 19 matched metastases were stained immunocytochemically for CD44H and products of variant exons v3, v4/5, v6 and v9. Patterns of staining in frozen and formalin-fixed tissue were correlated with invasive front grading and behaviour using exact inferential statistics. Most primary carcinomas stained for all exons tested but some showed loss of expression of v4/5. Loss of expression was more marked in metastases, but there was no correlation between expression and behaviour or grade. Stromal surfaces of epithelial cells often expressed variant exon products reflecting loss of polarity. This, together with selective loss of v4 and v5 in primary carcinomas and their more frequent loss in metastases, suggests that CD44 may play a role in metastasis of some oral squamous carcinomas.

Aged↗

Structure-function relationship of antibacterial synthetic peptides homologous to a helical surface region on human lactoferrin against Escherichia coli serotype O111.

Lactoferricin includes an 11-amino-acid amphipathic alpha-helical region which is exhibited on the outer surface of the amino-terminal lobe of lactoferrin. Synthetic peptides homologous to this region exhibited potent antibacterial activity against a selected range of both gram-negative and gram-positive bacteria. An analog synthesized with methionine substituted for proline at position 26, which is predicted to disrupt the helical region, abolished antibacterial activity against Escherichia coli and considerably reduced antibacterial activity against Staphylococcus aureus and an Acinetobacter strain. The mode of action of human lactoferrin peptide (HLP) 2 against E. coli serotype O111 (NCTC 8007) was established by using flow cytometry, surface plasmon resonance, and transmission electron microscopy. Flow cytometry was used to monitor membrane potential, membrane integrity, and metabolic processes by using the fluorescent probes bis-1,3-(dibutylbarbituric acid)-trimethine oxonol, propidium iodide, and carbonyl cyanide m-chlorophenylhydrazone, respectively. HLP 2 was found to act at the cell membrane, causing complete loss of membrane potential after 10 min and of membrane integrity within 30 min, with irreversible damage to the cell as shown by rapid loss of viability. The number of particles, measured by light scatter on the flow cytometer, dropped significantly, showing that bacterial lysis resulted. The peptide was shown to bind to E. coli O111 lipopolysaccharide by using surface plasmon resonance. Transmission electron microscopy revealed bacterial distortion, with the outer membrane becoming detached from the inner cytoplasmic membrane. We conclude that HLP 2 causes membrane disruption of the outer membrane, resulting in lysis, and that structural considerations are important for antibacterial activity.

Amino Acid Sequence↗