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Biomedical subjects

F M Beck

Publications and source records attributed to F M Beck.

At least 55 records · Page 3Linked to original sources

Resolution of candidal lesions of the dorsal rat tongue by ketoconazole.

The purpose of this study was to determine whether the mucosal alterations of the dorsal rat tongue produced by Candida albicans infection were reversible upon treatment with the antifungal drug ketoconazole. Following experimentally-produced infection, 17 rats showed clinical evidence of persistent lesions over a period of 20 weeks. Eight of these animals were then treated with ketoconazole daily for 2 weeks (20 mg/kg/day). Appropriate non-infected controls and ketoconazole-only controls were also maintained. Five weeks after the ketoconazole treatment, all animals were killed and the dorsal tongues evaluated clinically and histologically. Control groups showed no abnormalities. Of the 8 animals in the treated-lesion group, all showed lesional resolution, while only 2 of the 9 animals in the untreated-lesion group showed resolution of their lesions (p = 0.002). These findings indicate that the epithelial changes produced by this candidal isolate for this period of time are reversible.

Animals↗

Retained "hopeless" teeth. Effects on the proximal periodontium of adjacent teeth.

The retention of teeth diagnosed as periodontally "hopeless" may accelerate the destruction of the adjacent proximal periodontium. Studies determining the influence these teeth have on the health status of adjacent teeth appear nonexistent. It was the intent of this retrospective study to assess the status of the periodontium in adjacent teeth proximal to the periodontium of "hopeless" teeth. We evaluated 17 teeth, each being mesially adjacent to one "hopeless" tooth, in 17 subjects treated for periodontal disease. In each case, the "hopeless" and the adjacent teeth received the same treatment. Probing depths (P-D), radiographic alveolar bone level (R-BL) and the width of the periodontal ligament space (W-PL) were measured for both the adjacent interproximal and the nonadjacent interproximal surface for each hopeless tooth. At both pretherapy and posttherapy, there were no significant differences for any of the variables (P-D, R-BL and W-PL) for the adjacent interproximal surfaces with the nonadjacent interproximal surfaces. However, there was a significant reduction in the mean probing depth for the adjacent interproximal surfaces, pretherapy to posttherapy. No other significant changes were found in any of the other variables for either the adjacent or nonadjacent interproximal surfaces. These data suggest that teeth considered periodontally "hopeless" and retained have no effect on the proximal periodontium of adjacent teeth prior to and following therapy.

Bone Resorption↗

Testing reliability of plaque and gingival indices. Two methods.

This investigation was undertaken to compare two methods of interexaminer and intraexaminer reliability in the evaluation of Plaque and Gingival Indices prior to a study of toothbrushing. Inter-/intraexaminer reliabilities were compared using a projected slide series consisting of 40 slides of clinical examples of gingival inflammation and plaque accumulation. Time between assessments was three weeks. Using the slide technique, intraexaminer reliability was established for: (1) Gingival Indices and (2) Plaque Indices. Interexaminer reliability was also established for Gingival Indices. Interexaminer reliability could not be established for Plaque Indices on the first assessment but was established on the post-assessment. Intraexaminer reliability was also determined through clinical examinations of patients. A third clinician was used to manipulate the tissue while investigators evaluated bleeding on provocation and plaque accumulation. Significant results were established for the Gingival Indices and Plaque Indices. Results of this investigation suggest that significant inter-/intraexaminer reliabilities may be obtained for gingival indices using the slide technique. In addition, the clinic technique appeared useful for assessing interexaminer reliability for Gingival Indices. Plaque Indices using the slide technique required more practice than those using the clinic technique.

Dental Health Surveys↗

Influence of radiation therapy on oral Candida albicans colonization: a quantitative assessment.

An increase in quantity of oral Candida albicans was documented in patients receiving head and neck radiation therapy during and after therapy, as assessed by an oral-rinse culturing technique. The amount of the increase was greater in denture wearers and directly related to increasing radiation dose and increasing volume of parotid gland included in the radiation portal. A significant number of patients who did not carry C. albicans prior to radiation therapy developed positive cultures by 1 month after radiation therapy. The percentage of patients receiving head and neck radiation therapy who carried C. albicans prior to radiation therapy did not differ significantly from matched dental patient controls.

Candida albicans↗

Differences in mucosal reaction related to Candida albicans isolates.

In order to examine the behavior of Candida albicans in an oral mucosal model, 16 isolates of the organism were collected from a variety of clinical settings and were inoculated weekly, in equal numbers and concentrations, into the mouths of separate groups of 20 female Sprague-Dawley rats. Oral swabs were taken bi-weekly in order to monitor the presence of the yeast. After 16 weeks, the animals were killed and the tongues were examined grossly and histologically. Six isolates demonstrated the ability to produce characteristic dorsal tongue lesions to varying degrees (1/20; 1/20; 1/20; 2/20; 3/20; and 12/20). Of the remaining 10 isolates, 5 showed hyphal penetration of the keratin layer of the dorsal tongue epithelium, yet no mucosal reaction was elicited and no lesion was produced (1/19; 2/19; 4/20; 5/20 and 5/20). These findings support the concept that C. albicans exhibits a spectrum of mucosal pathogenicity for dorsal rat tongue.

Animals↗

Relation of stress and anxiety to oral lichen planus.

Stress and anxiety have frequently been mentioned as possible factors related to the development of oral lichen planus, although this association appears to have only an anecdotal origin. In this study, 48 patients with a clinical and histologic diagnosis of oral lichen planus completed questionnaires aimed at assessing their stressful life events (Social Readjustment Rating Scale) and their tendency for anxiety (the trait portion of the State-Trait Anxiety Inventory). Age- and sex-matched control groups included patients who underwent biopsies for irritation fibroma and routine clinic patients. No significant differences were seen among any of the groups with respect to scores on the questionnaires. These results suggest that patients who manifest oral lichen planus have no greater tendency toward anxiety and no more stressful life events than other individuals.

Adult↗

Effect of antimicrobial agents on root surface caries, alveolar bone loss, and microflora in rice rats.

Two antimicrobial agents, 9-aminoacridine (0.2%) and minocycline (0.2%), were evaluated for their efficacy in inhibiting root surface caries, bone loss, and microflora in rice rats. A solution of 5000 ppm fluoride was used as a positive control for the inhibition of root surface caries, and double-distilled water was used as a negative control group. Each rat was treated by having its molar teeth swabbed 2 X per day with the prescribed agent in its group for nine weeks. Root caries reduction in the minocycline and fluoride groups was not significantly different, but the reduction was significantly greater than in the 9-aminoacridine group, with the caries score in all three groups being significantly less than that in the water control. Bone loss reduction for the minocycline group was significantly greater than that for any other group.

Alveolar Process↗

Bone loss following periodontal therapy in subjects without frequent periodontal maintenance.

The longitudinal effects of periodontal therapy in patients without a frequent periodontal maintenance program have been minimally documented. In this study we used Duckworth's modification of the Schei Ruler Technique to assess the difference in bone level around individual teeth treated for periodontal disease in subjects receiving infrequent posttherapy maintenance (less than or equal to 1 time/year). Crestal bone height differences were evaluated using the initial presenting series of long cone parallel radiographs of 23 subjects with their subsequent posttherapy analogous radiographic series taken 5.4 +/- 2.9 years later. Bone loss was defined as a reduction in the alveolar crest of greater than 50% of the radiographic crown height which corresponds to approximately 4 mm in posterior and 5 mm in anterior teeth. The loss for each tooth was expressed as a per cent of the measured height of the crown after conversion from millimeters using the mean crown-root ratio for each tooth. We found increased alveolar bone loss and tooth loss in subjects examined posttherapy when compared with conditions present when each subject initially presented for periodontal treatment. Our data suggest that molar teeth are more at risk than incisors and cuspids and that a lack of periodontal maintenance care and inadequate plaque control contribute to progressive bone loss following treatment.

Aged↗

Role of tetracycline in pathogenesis of chronic candidiasis of rat tongues.

Forty female Sprague-Dawley rats were randomly divided into two groups. Group 1 animals received tetracycline solution (0.1% during week 1 and 0.01% thereafter) as drinking water, as in previous studies. Group 2 animals received double-distilled demineralized water. Animals in both groups were inoculated orally with an equal number of viable, mucosally pathogenic Candida albicans organisms. After 20 weeks, inspection of the tongues showed gross lesions in 16 of the 20 animals in group 1 and 17 of the 20 in group 2. These lesions were confirmed histologically. No significant difference in the number of lesions was noted between the two groups. However, the lesions in group 1 animals were significantly larger than those in group 2 animals. These results suggest that, given this mucosally pathogenic strain of C. albicans, the establishment of a chronic infection of the rat tongue is apparently not influenced by tetracycline-treated drinking water as administered in this study. This suggests that antibiotic exposure is not an essential factor in the pathogenesis of this lesion. A larger lesion area, however, does appear to be related to the use of tetracycline solution as drinking water.

Administration, Oral↗