Biomedical subjects
E D Theaker
Publications and source records attributed to E D Theaker.
Patterns of antifungal prescribing in general dental practice.
OBJECTIVE: To examine the current practice of antifungal prescribing by GDPs in the United Kingdom. Design A postal questionnaire circulated to a random selection of 400 dentists. OUTCOME MEASURES: The questionnaires were analysed and the responses expressed as absolute and relative frequencies. RESULTS: Responses to the questionnaire were received from 297 (74.3%) GDPs. Nystatin was the most popular choice of antifungal agent that GDPs would use, followed by miconazole, amphotericin B and fluconazole. The likelihood of use of miconazole was positively linked to recent date of graduation. Lack of knowledge regarding contraindications and problems with azole antibiotics was found in a significant minority of practitioners (36%). CONCLUSIONS: The present study indicates that azole antifungal agents (especially miconazole) are becoming more widely used by GDPs, but that knowledge regarding potential problems with their use is sub-optimal. Nystatin remains the most popular choice of antifungal agent.
Miconazole oral gel and drug interactions.
Miconazole oral gel is frequently prescribed for the treatment of oral Candidal infections. Its ability to be systemically absorbed and interact with other drugs has previously been recorded but is not universally known. As a reminder, a further case of derangement of anticoagulation following concomitant use of warfarin and miconazole is reported. Other potential drug interactions of miconazole and fluconazole are highlighted.
Adverse reactions associated with the use of eugenol in dentistry.
Eugenol is a material commonly used in dentistry with few reported side effects. It is not however, a bio-friendly material when in contact with oral soft tissues. It can produce both local irritative and cytotoxic effects, as well as hypersensitivity reactions. Here we report on two cases of adverse local reaction to eugenol, contained within a temporary restorative material and a temporary cementation material respectively, which illustrate these problems.
Delayed and immediate hypersensitivity reactions associated with the use of amalgam.
Hypersensitivity to the constituents of dental amalgam is uncommon. When it occurs it typically manifests itself as a lichenoid reaction involving a delayed, type IV, cell-mediated hypersensitivity response. Rarely, a more acute and generalised response can occur involving both the oral mucosa and skin. We describe two cases that illustrate the presentation and management of these two types of reaction.
Development and preliminary evaluation of an instrument designed to assess dental students' communication skills.
The aim of this study was to develop, and assess the inter-observer reliability of an instrument for evaluating dental students' communication skills. Methods used were process-tracking of interactions between experienced practitioners and patients, development of the instrument and its simultaneous use by two researchers observing 43 third year dental students prior to communication skills training. The results found that the instrument was appropriate for the purpose for which it was designed, and was easy to utilise. There were no significant differences between observers' total scores. Item-specific weighted kappa scores showed almost perfect agreement between observers for all but four of the 31 items. The lowest interobserver weighted kappa score was for the measurement of eye contact (k = 0.60). In conclusion, assessment of communication skills is now a necessity in the undergraduate curriculum. Preliminary analysis of an instrument of communication skills in the dental surgery indicates that it may be possible to do this reliably.
Carbamazepine monitoring.
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Phospholipid molecular species distribution of some medically important Candida species analysed by fast atom bombardment mass spectroscopy.
The aim of this study was to obtain detailed information on phospholipids (PL) of the medically important Candida species and to determine their possible chemotaxonomic significance. Lipids were extracted from 22 strains representing 8 Candida species and their PL molecular species distributions were determined by Fast Atom Bombardment Mass Spectroscopy (FAB MS) in negative ion mode. Fifteen major lower mass peaks (m/z 221 to 289) were attributable to the expected presence of carboxylate anions and 24 major higher mass peaks (m/z 557 to 837) were attributable to phospholipid anions. Major carboxylate peaks were of the following m/z and identities : 253, C16:1; 255, C16:0; 277, C18:3; 279, C18:2; 281, C18:1; and 283, C18:0. The most abundant peaks consistent with the presence of phospholipid molecular species anions include those of m/z 673, 743, 833, 834 and 836 tentatively identified as phosphatidic acid (PA) (34:1), phosphatidylglycerol (PG) (34:3), phosphtidylinositol (PI) (34:2) and two unknown molecular species. This profile is diagnostic for the genus Candida. Quantitative differences were observed between different Candida species. Thus, polar lipid molecular species distribution in Candida spp. has chemotaxonomic significance, especially so in the case of carboxylate anions.
Sensitivity of Candida albicans to negative air ion streams.
Negative air ions (NAIs) are known to kill C. albicans; however, their precise mechanism of action is uncertain. Elucidation of this has been hampered by a lack of reproducibility between results obtained by different investigators. The aim of this study was to determine the influence of variation in experimental parameters on the sensitivity of C. albicans to negative air ions and the role of ozone in this process. Ten strains of C. albicans were exposed to NAIs generated at different emitter distances, exposure times, relative humidities and under aerobic and oxygen-free conditions. In further experiments, ozone levels were measured under the same conditions. The effect of NAIs on C. albicans growth was assessed by measuring the area of the zone of inhibition generated around the electrode of the ionizer. There was a significant reduction in area of zone of inhibition with increasing emitter distance (P < 0.05), relative humidity (P < 0.05) or under oxygen-free conditions (P < 0.05). Increases in exposure time resulted in a significant increase in growth inhibition (P < 0.05). Ozone levels increased with increasing exposure times (P < 0.01) but were significantly reduced as emitter distance increased (P < 0.01). When utilized in a nonventilated room, levels of ozone produced did not exceed recognized safety limits. These results (a) demonstrate the importance of careful control of experimental parameters if reproducibility of studies involving NAIs is to be achieved, and (b) highlight the possible role of ozone in the microbicidal effects of NAIs.
Chronic sinusitis and zinc-containing endodontic obturating pastes.
Several researchers have reported a link between the development of a solitary antral aspergillus sinusitis and the presence of zinc-containing root canal obturating paste within the antrum. If diagnosed correctly, it is generally accepted that this type of sinusitis can be treated effectively using surgical techniques alone. However, previous reports have shown that this is not always the case and may result in prolonged and inappropriate treatment of the condition. It is hoped that the reported case and literature review will assist both dental and medical practitioners in identifying affected patients and in the subsequent instigation of correct treatment regimes.
Radiological appearance of clinical inflammatory sinus disease with bone destruction. The significance of contrast enhancement.
It is generally accepted that conventional imaging techniques have limitations in their ability to differentiate benign and malignant disease processes resulting in bone destruction. Although computed tomography (CT) has proved helpful in the diagnosis of such lesions in the paranasal sinuses, the underlying radiological criteria are unclear and the value of contrast enhancement appears limited. Conventional radiographs and CT scans, with dynamic contrast infusion, from five patients in whom a provisional diagnosis of antral carcinoma had been made were reviewed in the light of a subsequent histopathological diagnosis of benign inflammatory disease. In four of these patients, a band of enhancement was demonstrated to parallel the antral walls which, in three cases, remained intact despite underlying bony defects. Their finding is significant in that it demonstrates mucosal integrity, thus making the radiological diagnosis of antral carcinoma less attractive and allowing assessment of the extent of inflammatory soft tissue changes. Thus the use of contrast-enhanced CT is recommended in the assessment of patients in whom sinus disease with bone destruction has been identified on conventional radiographic examination.
The influence of post-filtration washing on the in vitro assay of Candida albicans adherence to human buccal epithelial cells.
A simple in vitro assay technique was used to determine the effect of post-filtration washing on the adherence of C. albicans (NCPF 3736) to human buccal epithelial cells (BEC). Washing was carried out with a range of volumes of phosphate buffered saline (PBS), viz. 0, 5, 10 and 20 ml, at a standard flow rate. Both the number of C. albicans adherent to BEC and the percentage of BEC with adherent C. albicans were significantly decreased (p < 0.001 for each of these measures) after washing with 5 ml PBS. Further increases in the volume of PBS did not significantly decrease either measure of adherence. These data indicate that only a small volume of PBS, 5 ml, is required to achieve the removal of non-adherent C. albicans from the surface of BEC. The result of the adherence assay is not significantly affected by increasing the volume of PBS used. It is concluded that considerable savings in time may be made through using only a small (5 ml) volume of washing buffer at a standard flow rate.
The possible influence of the menstrual cycle on the adherence of Candida albicans to human buccal epithelial cells in vitro.
Although the influence of the menstrual cycle on both vaginal candidosis and Candida albicans adherence to vaginal epithelial cells in vitro has been shown to be significant, similar studies have not been made on oral candidosis and adherence to buccal epithelial cells. The aim of this study was therefore to use an in vitro adherence assay to investigate the possible influence of the menstrual cycle on the adherence of C. albicans to buccal epithelial cells. Epithelial cells were collected from a single, healthy, female volunteer on days 5, 15, 22 and 28 of six menstrual cycles. Adherence of C. albicans was significantly higher to buccal epithelial cells collected on day 5 of the menstrual cycle when compared with days 15, 22 and 28, both in terms of the percentage of buccal epithelial cells with adherent C. albicans and the number of C. albicans adhering per 200 buccal epithelial cells in four out of six menstrual cycles (p < 0.001). This result indicates that hormonal influences should be considered when buccal epithelial cells are used in vitro to assess candidal adherence and may implicate hormonal factors in the aetiology of oral candidosis.